Bull1Iss6ArtIII


THE FOOD OF THE M LLER FRE H-WATER FL HE . 

BY H. A. FOREE'. 

In a pap r on th food of fi. h .:, publi h d in 1 0/· I chara ·-
t riz d th fo d f all th Illinoi A anthopt ri, with th ,·cep-
tion of th phr <l derid: p and in th pr en t arti l , which i 
to be r aard d a· a c ntinuation of that ju t m ntion ll, I prop , 
to urnmarize my ob rvation. n all th mall r fish s o · urina 
in the waters of th tate, with th xception of the dart r · 
(Eth o ·tomatin~), which wer tr ated in the pr c ding paper. 

The purposes and method f the investigation up n whi h th 
following discu · ion i ba ed, ar so similar t those already d -
cribed, that th y will not need any especial pr sent xplanation . 

The data for it have been obtained by a minut an 1 careful 
study of the content of th alim ntary canals of 319 p cim n ·, 
bel ngina to twenty-five speci ·, representing twenty-tw gen ra 
and seven families, namely: Aphrecloderich-e, C ttid, , Ga t rost i­
dre, Atberinidre, CyprinodonticL , Umbridre, and Cyprinid, . 

An additional feature is th cl cription f th stru tur s sub­
sidiary to alimentati n, given, in thi pap r, f r a h g nu , in or­
der to furnish a basi · for a more exact discu ion of the r lations 
of structure to food-habit than 1 att -mpt d form rly. Und r 
this head I have included th length and c mplicati n of the ali­
mentary canal, th chara ·t r f the pharyngeal stru tur , th 
number and <level pment of th gill-rak "' rs, and th pr nc of 
any peculiar pr hen il apparatn about the rn uth. 

First ivina for a h sp ·i s a bri f a count f it · numb •r and 
distribution throughout th tate, I shall adcl for a h a nu.· a 1 -
s ription of th e alimentary structur ·, f 11 wing thi · hy a <l -
tail d tatern nt of the ob •rvation · ma<l upon it f oc1, ancl 
clo ino- with a ·ummary of u ·h oh rvation , and a <li · u.· ion of 
the correlation · f structur to food chara ·t r , g iv n om time· 

;;; Bulletin o. , Ill. 'tate Lab. at. Hist., Pl. 18- 65 . .. 



66 The Food of the Snialler Fresh- Water F ishes. 

under the genus and sometimes under the special group to which 
the genus is assigned. 

FAMILY APHREDODERID.LE. 

T his family is represented by a single peculiar species ( Apli1·e­
cloclerits sctyctnits), resembling the sun-fishes in most of its char­
acters, bilt remarkably distinguished by the fact that the vent, 
although occupying the normal position in the young, opens in 
the adult far forward under the head, moving gradually to the 
front with increasing size. This fish is not over three inches in 
length. It occurs in rivers and smaller streams, as well as in lakes 
and ponds throughout the State. W e have collected it from the 
Illinois River and various tributaries, as well as from the lakes 
connected with that stream, and from ponds and creeks through­
out Southern Illinois. It has also been taken in the Calumet 
River near Chicago, and from lakes in that vicinity, but is not 
known to occur in Lake Michigan. It is said to be nocturnal in 
its habits, by Dr. C. C. Abbott, who kept specimens in an aqua­
rium for some time.-x- The same author reports that in confine­
ment it feeds voraciously upon small fishes, especially immature 
Cyprinidre ; and for this reason he bestowed upon it the name of 
pfrate pm·cli, by which it has become generally known among 
ichthyologists. The observations presently to be detailed will 
show, however, that his specimens were doubtless forced to feed 
so largely upon fishes for want of food more natural .to them; 
since in their native haunts fishes make but a small percentage of 
their ordinary food. 

The intestine of this species is short and simple, less than the 
length of the head and body without the tail, and distinguished 
only by the character previously mentioned. The gill apparatus 
is ineffective, the rakers being very short, thick, blunt, and few, 
and covered with short spirrnles. The pharyngeal jaws consist 
of small plates, covered with short, sharp spinulose teeth, similar 
to those of the sun-fishes. The mouth is large, but not remarka­
bly protractile. 

The specimens dissected number nineteen, representing seven 
different dates and localities, throughout Central and Southern 
Illinois. Some were taken from small tern porary ponds left by 

1*Proc. Phil. Acad. Nat. Sci., 1861, p. 95. 



Th Food of the maller Fl'esh- Water Fi hec. 67 

th r tr ating o,·erflow of str am oth r fr m p rman >nt lak s, 
and till o h r from ere k and ri Y r . · ' m the tliff r­

ent 1 caliti vane but li tl on th , hol an l it i · s ar cly 
worth whil to li cu· th :>parat col l ti ns. That of th . , 
nineteen sp cim 'n wa almo t pur ly animal tra •s of a rninut 
fiowcrino· 1 lant (Y\ olffia), antl small quantiti s of filam 11tous 

lgre ;1 ly bei1w tak n by two of H1 ·p' ·im rn·. Fishe wer 
eaten b, but two, and were r "ckoned at two p r ent. of tlie 
food of the whole. One of th e f un 1 wa re o·nizal le a. a n 
""yprinoid, but the othn could not be d t rmin <1. Ins ct 
amounted t more than nin ty p r nt., all of tbem aquati , with 

the xception of a few gnat (Culi idn~) tak n by eight f the 
fi he·. early half of the fo d consi~ ted f larv,--. of hirono­
mus :ind Corcthra. quatic ' leopt rous larne were recko1, cl at 
eleven per c nt., and specimen of Corixa, taken by thr e of th 
fi he at two. A ingl fi h had al o eaten Galgulus. A fourth 
of the food con i ted of n uropt rous larne (Ephemerid," and 
Libelluliclc ~) . Cru ta eans, thou ·h aptur d by more than half 
th fi he made but four per cent. of the food . A. far as r co ·-

o 
nized, thi element consiste 1 ·hie-fl of the am1 hipoc.l, Alto,· ·he ·tes 
lentata, and the c mmon i opod, A ellus. A f ,v sp cimen. of 

Cyprididm w .re noticed in two f the fishe , and ·•yclops and 

other op poda wer taken by five. One fish ha<1 eaten a 
Lumbriculu , a ·pe ies clo ely alli cl to the common earthworm . 

A careful omparison was made of th food of specirn 1is of 
, ariou :10- s- tho~ , consequently, in which the situation f the 
vent wa wid ly cli:fferent-but no diff .rences f foo<1 whatev r 
were cli tino·uishable. It is highly probable, ·on . qu ntly, that th 
explanation of this peculiar ·hara t r must b souf:,·ht else"vherc 
than in the food. vYith re pect to the other r latio11s of food to 
structure we have at present only to note the c 'inciden e of fi hes 
and aquatic insects a the principal lem ents f th~ fo c1 with the 

large mouth and inferior development of th g ill and pharyn_aeal 
apparatu , and hort an l simple intestine . 

F l\IILY COTTID.fE. 

Thi curiou family, chi fly marine, is repr ented in th 'tat 
by ev ral species fr m Lake Michigan, mostly from its t1e ,p r 

waters, and by a single one rece1:tly di ·covered in our streams. 



68 The Food of the Smaller Fresh - Water Fishes. 

POTAMOCOTTUS MERIDIONALIS, Gill. GOBLIN, BLOB. 

Although this fish has not hitherto been recorded from the 
State, we have found it abundant in small streams in Southern 
Illinois, and a single specimen has been sent us from McHenry 
County, near our northern limits. The first of these situations is 
in a limestone region, wbere small caves are not infrequent; hut 
the second is in an area deeply covered by drift, with rock no­
w here exposed. 

The general appearance of this fish is not unlike that of a cat­
fish, the head being broad and flat, the mouth very large, and the 
skin smooth. The gill-rakers are few, short and thick, and of in­
significant character; the pharyngeals are similar to those of Aphre­
doderus, but form thicker and larger plates; the intestine is short 
and simple, its entire length being less than that of the head and 
body. 

Six specimens of this species, taken in Southern Illinois, had 
eaten only animal food, about one-fourth of which consisted of 
fishes, one of which was furnished with ctenoid scales. Undeter­
mined aquatic larvre (thirty-six per cent.) and other insects, were 
estimated at forty-four per cent. of the food. Crustacea, all belong­
ing to the genus Asellus, eaten by two of the fish es, composed the 
remaining twenty-nine per cent. The general resemblance of the 
food of this species to that of Aphredoderus seemingly corre­
sponds to the similar character of their alimentary structures. 

FAMILY G ASTEROSTEIDLE . . 

Of the interesting little stickle-backs, two species were studied, 
only one of which is common in the State. 

EucALIA INCONSTANS, Kirt. BLACK STICKLEBACK. 

This fish is abundant in streams and lakes in the northern part 
of Illinois, but has not been taken by us south of Rock River. 

Its mouth is small; the gill-rakers are long and slender (about 
half as long as the corresponding filaments), but are not unusually 
numerous; the pharyngeal apparatus is insignificant or wanting; 
and the intestine is short and simple, not longer _than the head and 
body together. 



The Food of the Smallel' Fl'esh- Water Fishes. 69 

Four p ·im ns from hock River, and one from Ce<lar Lake, in 
L~ke County, had clivi lecl their food about equally between plant 
and animal substances: the f nner, consisting; wh lly of :filamen­
tous Algre, taken by four of the sp cim ns in quantities to make 
it certain that they were ingeste l purposely. The animal food 
was about qually ins cts and crustaceans, the former nearly all 
aquatic larv, ,, of Diptera (Chironomus b ing the commonest form), 
and the latter chiefly Entomostraca, of which Cladocera wer the 
most abundant. One of the specimens had eaten Cypris-some 
of them Cypi·is vidua. Cyclops was also noticed in three of the 
fishes, and amounted to three per cent. of the food. 

The herbivorous character f this fish seems not to be related to 
any structural facts; but the occurrence of the large ratio of En­
tomostraca is at once accounted for by the well-developed gill ­
rakers, these serving as a straining apparatus by means of which 
the fishes possessed of it are able to appropriate minuter organ­
isms than would otherwise be available for their food. 

PYGOSTEUS PUNGITIUS, Lac. MANY-SPINED STICKLEBACK. 

This species has hitherto been found by us only in Lake Michi­
gan, and in Calumet River near its mouth. 

But two specimens were dissected; and these had fed wholly 
on larvre of Chironomus and Simulium (sixty per cent.), and on 
Chydorus and other Cladocera (forty per cent.). 

With so small an amount of mat rial to illustrate the food of 
the family, we can only say that it evidently consists chiefly of 
aquatic larvre and Entomostraca, together with a considerable per­
centage of vegetable substances. In the absence of any appara­
tus for mastication, the latter will doubtless be found to consist of 
Algre, as in the cases examined. 

FAMILY ATHERINIDlE. 

LABIDESTHES 1ccuL u , Cope. SIL VER 'IDES. 

This elegant little fish, the only fresh-water representative of 
its family, is generally abundant throughout the State, and has 
been collected by us in a great variety of situations, from the 
northern lakes to the Wabash River. 

It is long and slender, the mouth small and well furnished with 



70 Tlie ·Food of the Srnaller Fresh- Water Fishes. 

t etl1, while the throat is destitute of special pharyngeal appara­
tu . The gill-rak rs are unusually well developed, being numer­
ous, 1 nder, finely toothed, and longer than th e corresponding 
:filament of the g ills. Taking into account the small size of the 
fish, and the consequently small diameter of the apertures of the 
mouth and g ills, it will be seen that it is provided with an espe­
cially effective straining apparatus. The intestine is unusually 
short, the entire alimentary canal measuring considerably less than 
the length of the body without the head. 

The following account of its food is derived from the dissection 
of twenty-five specimens, obtained from Crystal Lake, Fox River, 
and Calumet River in Northern Illinois, from Peoria and Mack­
inaw Creek in the central part of the State, and from Little Fox 
River in the Wabash Valley. The food of these specimens was 
purely animal, a little over half consisting of insects, and a little 
less t han half of crustaceans. The larvre of {;hironomus were 
among the most important elements of the food, standing at thirty 
per cent. of the whole. The crustaceans were all Entomostraca, 
and represented a great variety of both Copepoda and Cladocera, 
although none of the specimens examined happened to have eaten 
Ostracoda.. Among the Cladocera recognized were D aplinia 
pulex , 1·etrocu1·va and !iyal'ina,, Simoceplialus amm·icanits, Bosmi­
na, Chydorus, Pleuroxus, Alona., and Eurycercus; and among the 
Copepoda were Cyclops tlwmasi, Canthocamptus, Diaptomus, 
Limnocalanus, and Episckura lacustris. Spiders and terres­
trial insects, accidentally washed or fallen into the water (the 
latter including Chalcidida:> , various Diptera, plant-lice, Tettigoni­
dre, Thrips, and Podura), amounted to twelve per cent. of the food. 
The only peculiarities of food corresponding to differences of local­
ity were found among the group from the nort.hern lakes, in which 
the Chironomus larvre were present in diminished ratios, while 
the Cladocera were more abundant. 

FAMILY CYPRINODONTID..£. 

T his family consists, in Illinois, of four species, one of Fundu­
lus and three of Zygonectes.* The family is divided into two 
sections, ccwnivo1·ous and lie1'bivo1·ous, by Dr. Gi.i.nther in his "In-

-:;,r do not consider Fundulus menona, Jor. and Cope., as distinct. 



The Foocl of the maller Ft'csh- ll'11te1· Fishc, . 71 

troclu ti n to th tncly of ~ i 11 ' ·. ' ,.\.]though ur er n ra h th 
belon · to +-he arniv rous ecti n, it will h n that h y ar not 
by an m an tri ·tl ' nfin 1 t animnl f t1 " o- tati n mak­
ing ab ut one-fifth of th i.r u ual nutrim ' llt. 

BARI ED KrLLlFL u. 

Thi , pecies i V ry abundan in th n rth rn part f th tate, 
p ciall in lak r in cl ar aml am1y ·tr am , but , ha 1) t 

taken it anywber In ntral r OU th ' l'll Illinoi . M t f ur 
oll ctions were mad In the lake f Lak an l I H nry un-

ties. 
The intestine is hort r than the body, th gill-rak r are Ii rt, 

btu , and few in number, th phary1w al jaw ar f th 1 a -
ment type, et with fine, harp t eth, and the m uth i mall, but 
xtraordinarily protra til . 

Ei ·ht specimens were stu lied, fr m ~ry tal and edar Lak . 
\..bout four-fifths of the food c n ·i ted of animal ul tanc, , th 

remaining fifth of v o·etation. Except a few filarn nt us lgre 
taken by ne of th pecim ns, the latter nsi t cl wh lly 

f e ds of variou · plants fallen into th wat r. Ei ·hty p r nt. 
of the food of two of the specim ns, and tw nty p r ent. f that 
fa third consi te<l of su ·h els; ratio· vicl ntly t large to hav 

b en taken accidentally. Two of the p 'im n had aten Plan­
orbi., and all had eaten in ct , which macle ab ut f rty p r nt. 
of the food; terrestrial species, in luding pid r , maki1w tw lv 
per cent. mong th aquati forms were Chironomu larvn: , Hy­
drophiliclm, and larv, , of Ephcmerict~, th latter eleven p r nt. 
Cru ta a were a fifth of th fo d, chi fly tile abundant :unphipod, 
Allorcli st .s d ntata. ypn anc1 and na wer lik w1 n ti ed 
in considerable quantity ( ev n per cent.), ·an 1 a f w p im n ' of 

various ladocera oc urretl. 

ZYGONECTES .L OTAT ·, Raf. T P MINN w. 

This pecie ranges in pond and luggi. h str ams tbrou bout 
the State, but is most abundant uthwards. H re it may om­
monly be seen swimming slowly about in tagnant p 1 , with th 
head at the surface of the water, a if interested in th ph nomena 
of the weather, or p ibly wat hing for th app aran e of t rr -
trial insect·. The alim ntary trn tur · a.r in all r' l e t similar 



72 1'he F ood of the Sm,alle,· Fresh- Water Fishes. 

t tho f Fundulus, exc pt that the intestine is po sibly a littl 
lon o- .. r, b in · about qual to the head and body. The only strik­
in<Y p culiarity i the depr ssed head, with the mouth pla eel at the 
upper angl ancl opening obliqu ly upward. Thi , with the urfa -
swimming habit of the fish, has given rise to the suppositio11 that 
it fe d largely upon surface insects; but I did not find this to be 
the ca e, as the seventeen specimens studied contain no example 
of an insect of this character. 

These specimens were taken from a considerable variety of situ­
ations throughout Central and Southern Illinois, and at various 
times of the year. The animal food amounted to about ninety 
per cent. of the whole. Vegetation, almost wholly filamentous 
Algre, was taken by ten of the specimens, but in such quantities 
by various individuals as to make it certain that its presence was 
not accidental. In one, for example, the intestine was packed 
with these Algre to the exclusion of all other food, and in three 
others this made more than half the whole. One specimen had 
also eaten Wolffia. Mollusks (Physa) had been eaten by three, 
and insects amounted to seventy-three per cent. Spiders and 
various terrestrial insects made fully a fourth of the food. Philhy­
drus, taken by three of the specimens, was reckoned at eight per 
cent. Corixa and other aquatic H emiptera amounted to eleven 
per cent., and larvre of Agrion to three. Crustacea were esti­
mated at only six per cent. They included G1·cingonyx gr ic'ilis, and 
various Cladocera, Ostracoda and Copepoda. Among the Euto­
mostraca recognized were Daphnia, Chydorus, Pleuroxus, Acro­
perus, Cypris, and (;yclops. Chironomus larvre were about one 
per cent., taken by only two of the specimens. 

ZYGONECTES INURus, Jor. and Gilb. BLACK-EYED ToP MINNOW. 

ZYGONECTEs DISPAR, Ag. STRIPED ToP MINNOW. 

The first of these species is peculiar in this State, as far as 
known, to Southern Illinois, not having been taken by us north of 
White County. The second ranges throughout. 

Six specimens of the first and two of the second were studied. 
The food characters presented do not differ sufficiently from those 
of Zygonectes notatus to make it worth while to treat them sepa­
rately, and a summary for the g enus will be given instead. 



The Food of th e maller Fre, h- Water Fi he . . 73 

Four-fifth f animal matt r 
Il arl · n -quart r b in h • a Plan rbi . 
anc.1 T .... a/ •rrtu ,• i nc ru . than half a11c1 11 arl , 

half of th f t rr larva~ u ually 
o al nntlant in th f d f in UIT tl h r 

in nly triYial quantity. n o hilh ·dru at n h 
thr f th fi ·hes. Ol'i.m altenwt(( am unt l to fiv p r nt. 

f th ir f c.1, \. rion larv, and a w rm (L pto ridn.>) t tw 
p r nt. "'ru ta ean four p r nt. of th wh 1 

artly .t: mphi1 c.la, hut En om traca. Th v g tabl 
f ocl ( ixt n p r ent.) wa: hi lffia, tak n b , fiv f th 
p 1m n fr m outh rn lak 1 n indivi luals hac1 h w v r 
at n filamentou lg 

S u m m a 1· y . 

Th only es ntial cliff r n b tw n th two g n ra xhib-
it cl b · the p cim n tu li cl i th mu h larg r rati L of t rr . -

trial in · ct aptured by Zyg n t s, thi · genus ating n arly 
t\vi' a. many as the oth r. Thi. fa t i. po · ibly r lat d t th 
urfac - wirnrnina habit already m ntion cl, l ut i · m r lik 1 lu 

to th mailer boc.li · of wat r in whi h the t p rninn ws ur. 
on ernina th food of th family a a whole, the alient chara -

t r are th presenc fa onsitl rabl quantity of v ,aetable food, 
(al out tw nty per ent.) th oc urr nt f fifteen p r nt. of Iol­
lu a th in ignificant quantity f 'ru tac a aten (four p r nt.), 
ancl the importance f terr trial in ect a. a sour f uppor . 

F MILY MBRIDA3; . 

.MBRA Lnn, K irt. :\Iu1 J\Irr x w . 

Thi p cie the nly on fit farnil in Illinoi , i v ry al unc1-
ant in muddy pond and dit h ancl ha be n 11 t , (1 by u 
from Lake to mon unties. 

The inte tin i hort, le than th ho 1 ' in 1 · 11gth · th ·ill-
raker are thick and rath r 1 ng about n -half h length f th 
filam nt and the pharyng al a1 l aratu i wholl in. ianifi ant . 

T n . p cimens wer tuiliecl from ,· ix 1 alitif' all from outh-
rn Illin oi hut one, whi h wa. tak n in 'alum t Riv r. c>gc•ta-

bl food amount d to forty p ,r >11t . hi fl · olfiia at •11 I y 



74 The Food of the Smalle1· F1·esh- Water Fishes. 

seven of the specimen· fr m outhern Illinois lakes. A consider­
able quantity of uni ellula,r Algre was also taken by one. Mol­
lusks, eaten by two, were reckoned at five per cent., all Physa. 
Insects drop to fourteen per cent., chiefly undetermined larvre . 
No terrestrial forms w re recognized. Corresponding to the 
greater development of th e gill-rakers, we :find the Entomostraca 
assuming greater importance in the food. These were r ckonecl 
at ten per cent.; three per cent. additional consisting of (h·an­

gonyx yracilis. 

FAMILY CYPRINlDlE . 

This family includes all the fishes properly known as "minnows," 
embracing, in fact, by far the larger part of the smaller fishes of 
the State. Both in number and in variety of species it is much 
the most important family of fresh-water fishes. It includes, in 
Illinois, about forty species, nearly or quite one-fourth of the 
whole number known to occur in our territory. They occur in all 
waters from the Mississippi River and Lake Michigan to the 
smallest streams and ponds; but are much the most abundant in 
creeks and rivulets. The species differ greatly with respect to 
their favorite haunts, some affecting the principal lakes and larger 
rivers, others occurring most commonly in clear and rapid brooks, 
while still others are most frequent in the sluggish and muddy 
streams of prairie reg ions. The principal economic interest of the 
fishes of this family is due to the well-known fact that they fur­
nish an important part of the food supply of larger species. 

But little has hitherto been done upon their food in the United 
States. In fact, I have seen nothing more accurate or comprehen­
sive than the following general statement made by Prof. Cope, in 
his paper on the Cyprinidre of Pennsylvania :-K-

" These differences of habit are associated with peculiarities of 
food and of the structure of the digestive system. Few families 
of vertebrates embrace as great a variety in these respects as the 
present one. There are carnivorous, insectivorous, and graminiv­
orous genera, which are distinguished as among mammalia, the 
former by the abbreviation, the last by the elongation of the ali-

-:,,Trans. Amer. Philosophical Society, Vol. 13, New Series, page 353. 



J1 h,, Food of the 'mollt,· Fl'e-·l, - lf'rrtc,. Fi:he.·. 7n 

mcntar ' ·anal in tli form 'r th t ,th ar ' u ·uall · ·harp- •d(r d or 
hook d in th latt >r truucat hamm ' r, r p > u- ·hap 1.' 

In the in lucl d in th, · op, f 

thi p uliariti int tin rr p nd with th 
food. In th ~llbum ellu · 1·ubnfruns 1 they an but f ur-fi.fth th . " 

l n th of h ' acl and b dy ( x lulling caudal tin). In Jiyp ·ile-
pi · k ntukien is 2 Plwtug n is leucop ·, Al'.<f!JJ' us all' JW, l{, '

3 and 
na~ utus 3 Ericymba buccato ancl E. 'Ofjl s 'wn nut, ·illingu t a bout 

v n-ninth ; th f od f th la t fiv p ie i in t an 1 cru -
tac an the la t cl p ndinb largely on m llu · a. In the p i 
of ratichth · emotilu and Hyb p i with HyJ il 7Ji · cor­
mctu 4 fifte n- ixte nth t qual the l n ·th; th habits in tiv-
rou . The g nera with lon ·er int tin are fir t, till 5 on and 

t"o-£fth to on and thre -fourth the 1 ngth; hro mu , H ybor­
h ·nchu , and Pim phal s two and two-fifths to two and two-third , 
and Hyl o ·nathus f ur tim . The int tin in th ar g n r­
ally filled with a oft, dark- olored lime without remain of 
in ect but of " · tabl on gm. In th r markable g nu · 

1amp toma the anal ext nrl. · to betw n ei
0
·ht and nine im 

th 1 ngth and lik that of ther v g tabl feed r i u ·ually 
found o cupied by the ino-e ta for a con iderable part f it 
length .' 

Thi tatement i m the main corr t as far as it go s, but it 
will b seen from the foll wing data, and from the 1i u i n of 
th food of the family, that it is far from th truth with r . p t to 
the genu ampostoma an l its alli s. 

If we examin tl1 e alim ntary tructur s f the '1yprini 1~ , to 
whi h refer n e has b en made in de ribing the fo d f t h pr -
ce liner famili , we hall find these fi h a ily <livid 1 into at 
lea ·t four tol rabl di tin t gr up , defin <l by chara t r lrawn 
from the gill-raker , the phary1w al te th and the int ·tin . In 
all but two of th o- nera f this paper·X- th aill-rak r ar hort 
an l in ignifi ant. Th phary11g al t th may b ith 'I' h ok cl or 
plain, and with or with ut grinding urfa" , whil th int hn 
an in length from le than that of th l o<l with ut th h ad 

- ------- --- ---
1 finnilu or N otropi . ~Photoo-eni analo tanu . 3Rhinichthy.. 4Lux­

ilus cornutns. 0 Notemigonu . 
-:', I have use<.l her , for on venien e' sak , th no men latnr of the 

CaL:1)0,•·ue of the Fi h of Illinois, pnbli h l in our third bull tin. 



76 The Food oj the Smaller Fresli- Wate1· Pislies. 

t o seven or eig ht times the leng th of the head and body together. 
For convenience' sake I have g rouped the g enera as follows: 

Group !.-Intestine long. Pharyngeal teeth not or slightly 
hooked, with grinding surface. 

Oampostoma_, P imephales, Hyb01·hynchus, I-Iybognath:us. 

Group II.-Intestine rather long. Teeth hooked, with grinding 
surface. · 

Notemigonus, Olw·osomus. 

Group III.- Intestine short. Teeth hooked, with grinding sur­
face. 

Hybopsis, L uxilus, Lythrurus, I-Iemit1·emia, Platygobio. 

Group IV.-Intestine short. Teeth hooked, without grinding 
surface. 

M innilus, Photogenis, Ericymba, Phenacobius, Semoti lus, 
0 eratichthys, Rhiniclitliys. 

The second group, consisting of N oternigonus and Chrosomus, 
may be again divided according to the development of the gill­
rakers, which are numerous, long, and slender in Notemigonus; 
few, short, and insignificant in Chrosomus. 

Foon OF THE y OUNG. 

The g enera and species of Cyprinidre are not easily recognized, 
even in the adult, the characters upon which they are based being 
often either trivial or extremely variable; and when one has to 
do with individuals small enough to show the earliest food of the 
family, it is commonly quite impossible to identify even the genus. 
In the fe w specimens which I have studied, I have not attempted 
such determination, although I have reason to believe that most 
of those examined belong to some species of Minnilus. 

Their food was so far peculiar, _as compared with the young of 
other families, that I will describe in detail that found by dissect­
ing six specimens under an inch in length. The first of these, 
three-eighths of an inch long taken in Fox River on the 8th of 
July, had eaten only a small Chironomus larva, and a single ex­
ample of Bosmina. Two specimens, six-tenths of an inch long, 
captured in August in a creek in Central Illinois, had derived 
their food from quite different sources. Filaments of Spirogyra 
and other :filamentous Algre, cells of Cosmarium and Closterium, 



The Food of th maller Fresh- Waler Fi h , . 77 

and matopleura an l r diat m an 1 p r tilao-o w r 
th v g tabl l ment , whil th h ad f a 

o-r at number f th iliat infu rian ~~Uf!I 1 11<t 1,i1'idis and a 

few p im n of Eugl 'nlt l ·u ·, r pr n d th animal ki11,?"<l m. 
Full half th ont nt f th int f th r to-

zoa m nti ncd. third p im n f th tak 11 from 
th Illin i River in Jun , had 1 riv cl ab ut · it 
f tl from Bo mina, th remain<l r on i ting 
mu lan·a and a minut larval h clra hnitl. In a p 'im n 

tenth of an in h l ng, tak n in Ma :kinaw r l in Auo·u t, Elt­

gl JUl vii'idi<3 wa th mo t abun lant obj ·t, 
tenth of th fo d; anl Eugl ,ni rt·u' and a 

al o c urr cl. arious filam ntou lg,... p imf>n 
ium and o marium, and numb r of cliat m w r th remarnm 

elem nts. In anoth r specimen, tak n at th am . tim and 
pla e, about three-fourths of an inch in length, fungi and fmwu 
spor amounted to m re than half the food, altb u ·h the am 

f rms of Algre o urre l as befor , together wi h a f 'W example 

of Eugl na vil'iclis and Diffiugia. A Chironomus larva, a 1 lant­
l u e, and ome other inse t not determined, ha·d al o b en at n. 

From th above we may conclude that the oun yprini<l, 

draw almo t indi criminat ly for their food supply, upon Protozoa, 
Algre and Entomostraca, cliff rin in this respe t from th youno· 

of all the oth r families which I have tudi d, , ith th ex ption 
of th Cat stomidre. It i worthy f note, a a uo-o- tiv co111-
ciden at least, that the other families just mention ~a , hi h were 
found to take Entomostraca and hironomus larva~ a th ir arli­

e t food, were all po sessec.l of raptatorial t eth on the jaw wh n 

v ry younn; whereas in youno· u ker anc.l yprinitl, ~ th mouth 

i unarmed at all age . 

GROUP I. 

Inte tine long. Pharyngeal teeth not hooked, with grindino- urface. 

A IPO, TOM.A. ~ }IA.LU r, Raf. 

Thi· very peculiar fi h i xc din ly abumlant v 'r wh 'r x-
c pt in the great lakes. I have tak n it in tream f all mao-ni­
tud fr m the Illinoi Ri, er to th . mall t er k l nt haY not 
yet nc unter ct it in Lak Iichio-an r in staanant p ol . It i. 
commonest, however, in swift ere k of medium sii . 



78 The Food of the Smaller Fresh- Water Fishes. 

It i di ·tin o- ui h d fr m all other p i by the o-reat 1 no-th f 
;:') ::::, 

the int tine, whi h is fr m six to nine tim s the length of th 
hocly, ancl is spirally coiled about the air bladd r. Th gill-raker 
are numerou , ab ut twenty in numb r to ea h gill, but are very 
hor , arcely pr j ecting beyond the anterior margin f the arch. 

They are evidently almost totally inefficient as a straining appa­
ratu. 

Of the great number of specimens availabl e for diss ction, only 
nine were studied, since the contents of the intestines were founcl 
so uniform in character that it was not deemed worth while to 
multiply instances. These ;were from both extremes and also 
from the center of the State, ·but were all taken in July, August 
and eptember. The intestine was invariably filled from end to 
end with a black and slimy matter, which, when examined under 
the microscope, was found to consist almost wholly of fine mud. 
When the intestine was emptied and the contents . stirred up in 
alcohol and repeatedly decanted so as to separate the coarser frag­
ments, the org anic matter was easily distinguished. It made on 
an average, only about one-fourth of the contents of the intestine, 
the remainder consisting of the finest particles of sand and clay. 
Not far from one-fifth of the whole amount was of veg etable ori­
gin, consistiug chiefly of filamentous Algre, mingled with a few 
diatoms, but comprising occasionally minute fragments of other 
kinds of vegetation also. The only animal objects noted were 
occasional Chironomus larvre and Diffiugia. Sometimes the intes_: 
tine was wholly filled with almost pure mud, in which no organic 
structures whatever could be detected. Date and locality seemed 
to make no material difference in the food of this £sh, which 
should evidently be classed as limophagous. The ratios of ani­
mal to veg etable food were scarcely different from what one would 
expect to find in the intestine of a fish which had the habit of 
swallowing mud rich in organic matter, the greater ratios of vege­
tation being apparently due to the fact that plants are more abun­
dant in the water than animals. 

PIMEPHALES PRO rnL.As, Raf. BLACK HEAD. 

This species is generally distributed throughout Central and 
Northern Illinois, but is not very abundant. We ha Ye taken it 
only in rivers and larger creeks, but have not found it south of 
Jersey County. 



The Food of the maller Fresh- Water Fi hes. 79 

The a limentar canal i two or thr · tim the 1 n th f th .... 
b d ' and the gill -rak r ar £f n in numb r and om what 
rnor prominent than u ual, those n th o t rior pa.rt of the fir t 
ar h bein · about on -third th 1 no-th f th orre p nding fila­
ment. 

Only four pe imen tu died on from th P a tonic a 
RiY r at Freeport and three from tter reek in J r y ounty. 
\Vith this fi h a with the pr ceding, ab ut thr e-f ur hs of th 
content of the int tin con isted of mud, th remain 1er being 
almost wholly in ects. Th se were partly terrestrial pe ie , oc­
currina accidentally in the water, and partly aquatic larv. f Dip­
tera. The vegetable food of these pecimens amount d nly to 
about one per cent., biefly various unicellu lar Algre. 

HYBORHYX H s OTATU • Raf. BL NT- ~o ED MrN ow. 

This extremely abundant minnow occurs in tream · and riv r 
throughout the tate, but has not be n found ?Y u in p nd . 

pe imens were taken, however, in the mall lak s of orthern 
Illinoi . 

The intestine i about two and on -half times the length of 
the head and body. The gill-rakers are few short an<l thick, 
being about one-fifth of the length of the orre ponding £lam nts. 

Nine specimens were studied from all part of the tate, when 
th fr food proved to be so uniform in character that further obser­
vations were deemed unnece ·sa.ry. Mud made about eighty per 
cent. of the contents of the alimentary canal, the remainder con-
isting of unrecognizable vegetable debris, with a few filament 

of Alo-,~ . ndeterminable insects oc urred in on , and a inglc 
specimen of Cypris in another. 

HYROG ATH NUCHALis, Ag. BLUNT-.JAWED ML ~OvY. 

This species is likewi generally distribut cl in river , reeks 
and pond , occurring in our c 11 tions from Gal na t air , a.nd 
at a great number of points interm diat . 

The alimentary canal in thi genu i elongat , b ing about four 
times the length of the b dy. Th gill-raker are f w ancl ratb r 
short, triangular in form, and about on -fourth o on -fifth th 
length of their corre ·ponding filam nt.. 

Eight specimens of this speci wer ili s ct d with r ·ults in 



80 Th Food of the Smaller Fresh- Wat. r Fishe . 

all respects similar to those given for the other members of this 
group. Filamentous Alg , diatoms, and a few accidental fungus 
spores, were the only objects found imbedded in the quantities of 
mud which filled each intestine. 

SUMMARY OF THE GROUP. 

If we average the r sults of the four species studied, belono-ing 
to this first gr up, we shall find that about three-fourths of the 
contents of the stomach and intestine consist of soft, black mud, 
the remaining fourth being derived from both animal and vea table 
substances, about three times as much from the latter as from the 
former. The animal food is chiefly insects, both terrestrial and 
aquatic, and the vegetation is divided about equally betwe n Al­
gre and miscellaneous fragments of higher plants. This group, 
with long intestine and grinding pharyngeals, is consequently to 
be considered as essentially limophagous. We find this peculiar 
form of pharyngeal teeth associated only with intestines of this 
type. 

GROUP II. 

Intestines moderately long; pharyngeal teeth hooked, with grinding 
surface. 

CHROSOMUS ERYTHROGASTER, Raf. RED-BELLIED DACE. 

This species is locally abundant, although not generally com­
mon. It occurs in clear streams in the northern part of the State, 
but has not been taken by us in Central or Southern Illinois. 

The length of the fish is contained one and two-thirds times in 
the length of the intestine; the gill-rakers are few and rather short, 
triangular, acute, and about one-fifth the length of the corre­
sponding filaments. 

I examined carefully but three specimens of this species, de·­
.rived from two localities. These were alike in the presence of 
great quantities of mud, which amounted to about eighty-seven 
per cent. of the contents of the intestine. The animal food was 
confined to a trace of Cladocera. The vegetation a.mounted to 
thirteen per cent., partly tissues of aquatic plants, with traces of 
fungi, but chiefly Algre of various forms, including a little Oscil­
latoria. 



The Food of the mallet F,·e h- lVctte1· Fi he,·. 1 

TE;)IIGO ... HRY LE , i\Iit h. HI ER. 

Thi xtrem ly abundant minnow, commonly •all d the bin r, 
o urs in all waters throucrhout th tat , from the larg st riv r 
t th mall t ere k , and from Lak fichi an to mall stagnant 
ponds. 

Th int tin i horter than in any of th pr c ding speci s, 
althou h till rath r 1 ng, the head and body b ing c ntain d on 
and n -thircl time in it I ngth. The crill-rak r ar long, fin , 
and numerou , about tw nty in number on th anterior arch, and 
full one-third th I ngth of th corresponding filam nt , making, 
th refore, an ffective apparatus for the separation f the Ento­
m traca from the water. As this fish pres nts a peculiar combi­
nation of alimentary structures, and as it f d was found unusu­
ally Yariou , a larger numb r f spe im ns w r studied than f 
an of the sp cies already discu sed. 

Tw nty-fiv :fish w re diss cted, from a gr at vari ty f it­
nations in all parts of the State, and repr enting variou dat s 
from 1\Iay to eptemb r inclu ive. As th f od cliff r d widely 
a· orcling to ituation, that of specimens fr m c rtain localiti 
being more widely different than the food of different sp 01 

ha usually been found, it will be best to mention th most n-
pi uous differences depending upon situation. 

p cim ns taken from the Pecatonica River at Freeport, an 
extraordinarily muddy stream, noted for th abundance f it 
rnollu k , had at n no oth r food than univalve follu ca, hiefl 
Vctl1 rlta tl'icarinata an l Plan01·bis deflectus. An ther, from the 
Illinoi Ri,,er at P kin, had al eaten lar ly of mollu k , , hi! 
three taken in Ott r reek in J rsey C unty, in almost stagnant 
reache of the stream, extrem ly muddy, and gr en with Al 
hacl fill d their intestines with mud, lik Camp stoma; and still 
others from ponds n ar N rmal had aten only Entomo traca, 
about qually ladocera and Copepoda. Anoth r sp cim n fr m 
th Illinois River had taken imilar f od, all Daphnias. One pe i­
m n from ipp rsink Lake, in the northern part f the tat , wa 

full of wild rice (Zizania). Taking all the groups to th r, an 1 
consid ring the sp cies as a whol , b i 1 the mud air a<ly m ·n· 

ti ned, about fourt en per c nt. of th food n i t d f m llu l 
and only six per cent. of in ct , n arly all f whi h w r f 



2 The Food of the Smaller F1·esh- Water Pi hes. 

terr trial peci s. Crustac ans amounted to fift en per cent., all 
Entomostraca. Veg tation stands at fifty per cent., more than 
half of it accidental vegetable debris, partly from aquatic and 
partly from terrestrial plants. About one-fifth of the food con­
sisted of Algre, half of which was filamentous in character, and the 
remainder desmids, including Closterium, and various diatoms. 

The peculiar character of the alimentary structures of this 
species are very clearly reflected in this summary of its food, the 
elongate intestine corresponding to the presence of mud, and the 
well developed gill-rakers to the occurrence of Entomostraca. I 
have not yet noticed any structural peculiarity of the Cyprinidre 
related to the habit of feeding upon mollusks. 

SUMMARY FOR THE GROUP. 

The two species foregoing agree only in their mud-eating pro­
pensity, -probably habitual in one and occasional in the other,­
the first having the longer intestine, and the second the longer 
g ill-rakers. To this last difference we doubtless must trace the 
different relations of these fishes to Entomostraca. 

I find nothing whatever, by comparison of the food of these 
specimens with those of the preceding group, to show the mean­
ing of the hooked form of the pharyngeal teeth. 

GROUP III. 

Intestine short, teeth hooked, with grinding surface. 

This group includes Hybopsis, Luxilus, Lythrurus, Hemitre­
mia, and Platygobio. My studies were limited to three genera: 
Hybopsis, Luxilus and Hemitremia. 

HYBOPSIS HUDSONIUS. Clint. SPAWN-EATER. 

This fi.J). e minnow is common everywhere to the northward, 
especially in Lake Michigan and the other lakes of Northern 
Illinois, but not abundant south of the central part of the State, 
although it has been taken to its extreme southern limit. It has 
never occurred in our collections in the smaller streams, but 1s 
confined to the lakes, rivers, and creeks of some magnitude. 

The gill-rakers of this minnow are short and few. 
Seventeen specimens were studied, from Lake Michigan, 



The Food of the mall r Frel:!h- IVitt 1· Fishes. 3 

.1. Tipp r ink Lak and th Illinoi Riv r. Iud wa · found inn ti• -
abl qua11titi only in a iugl p im 'n, and th 'r in ·mall 
am unt. bout · v nty p r nt. f th d · <l f animal 
uh tan thr per ent. b ino- :fi h ·, taken by two f th 

mum wr:,. On had al o at n a mall bivah· mollu k. In · ts 
ma]' half the f cl, ab ut ne-thircl of th m of t 'IT ·trial p 1 • 

(Rhyn hophora) th r maind r b in<J' hi fly lan·,, of 'ph rn •ricl ·. 
f w Cbironomus larv:, ancl. an aquati h mipt 'r, w r th nly 

other kind det rmin d. Crustacea amount cl t thirt 11 p r • ut., 
n arly all O tracoda ( Oypri::; vicbta,) tak n by two f the p 'ci­
m n from Chicago. V g table f od tand · at thirty- n p r 
c nt. eat n by ten of the specim n . One-thircl f thi consist cl 
of Alg .. , chiefly of the filam ntous f rms, th remaind r I 111g 
mi c llan ou fragment of exog nous pla:1ts, hi fly viJ. ntly 
aquatic. 

Lo al and indfv·idual pecnli irUie . . - The gen ral ummari of 
th food f so many individuals from so great a variety f situations 
oft n clisaui e interesting and important facts relating to th food 
re ources of the species, sin e an el ment tak 11 in larg quantity 
by on or two sp cimens may figur in the gen ral averag rn 

uch an insignificant ratio as to lead to the infer no that its 
occurrence is merely accidental. In oth r w nl , general av mg 
for a variety of situations will not n essarily inclicat ' all th food 
re ources open to the species. The an only I dem n trate l 
by exhibiting the pemliariti s of th record as w ll a· its 
gen ral average characters. For xample, the fact that nly 
eleven per cent. of the food of this p ci s consi t cl of Alg, has 
a omewhat different asp ct when we I arn that one of the p ci­
men had eaten nothing else, ancl that they mad thr 'C-f urth of 
th f od of another. Three specimens had at n only in ·t , a.nd 
these made ninety p r cent. or mor of the fo cl of th r e oth r . 
Two had eaten nothing but Entomostra a, all the ('yJ ris nid1w 
pr >viou ly mentioned. V tabl tru tur made tit ntir' f od 
of f ur, and · ninety p r cent. or mor of the f d f hr e otb r 
sp 1m ns. Three out of f ur individual tak 11 at ipp r ink 
Lak in May, had d riv d from nin ty to n hunclr d p 'l' nt. f 
their foocl from t rr trial 1 tle8 f a in I fami ly (Rhyn hoph­
ora), while phemerid larv o curr cl in th f cl f thr oth r in 
ratios exceeding seventy-five p r ent. 



4 The Food of the Srnaller Fresh - TVater F ishes. 

HYB r J • • TRAMINEus, _Cope. STRAW-COLORED MINNOW. 

Thi in ·io-nificant species has been found by us in rivers and 
small streams throughout the State. 

The g ill-rakers were few and short. 
Only fiv e specimens were studied, all from rivers in Central 

Illinoi . About three-fourths of their food consisted of animal 
matt r, nearly all neuropterous larvre (fifty-eight per cent.), 
Ephemerid::e standing at forty-eight per cent., and case-worms at 
ten. Crustacea were ten per cent., all Cyclops except a trace of 
Canthocamptus. About one-fourth of the food was vegetation, 
chiefly seeds of grasses, occurring, of course, only accidentally in 
the water. Two had derived from ninety to one hundred per cent. 
of their food from ephemerid larvre, and four of the five had eaten 
vegetation amounting to as much as eighty per cent. 

LuxILUS CORNuTus, Raf. SHINER. 

'l'his large and fine minnow is probably the commonest fish in 
Illinois, occurring in lakes and streams of all sizes everywhere 
throughout our limits. 

The gill-rakers are short and few, and of insignificant develop­
ment, and the intestine is shorter than the head and body. 

Twenty-one :::pecimens were studied, from all parts of the 
State and at various seasons of the year. Animal food amounted 
to two-thirds of the whole, fourteen per cent. being fishes, eaten, 
however, by only one of the specimens. Insects, eaten by 
nineteen, were reckoned at forty-five per cent., only one-fourth of 
them terrestrial. Gyrinid larvre, Corixa, and larvre of Palingenia 
bil-ineata we~e among the forms recognized. The crustacean 
ratio was insignificant, standing at only three per cent., all the 
abundant amphipod, A.llorchestes dentata, with the exception of 
traces of a considerable variety of Entomostraca, incl~ding 
Chydorus, A croperus leucocephalus, and Cypris. One of the 
water-worms (Lumbriculus) was noticed in a single specimen. 
V eg etabl e food was reckoned at thirty-eight per cent., only about 
one-third of it consisting of Algre, and the rest of accidental 
fragm ents, including the seeds, anthers, and pollen of plants, with 
a little Potamogeton and various forms of fungus spores. One of 
the commonest of the Algre was Cladoplwra glomerata,* taken 

1*Kindly determined for me by Rev. Francis Wolle, Bethlehem, Pa. 



The Foocl qf l he malle,· FreBh- TVrtter Fi he . 5 

1 ' tho e fr m •Effingham. Th fa t ha alr ad b n n t cl that 
f th p im 11 ha l •atcn nl fi h . Fiv had nfin d 

th m · lv · an m · t di t whil tw Iv bad 1 rn· d m r than 
ltalf their food fr m th v a tab) kinaclom, on of th m atin 
nin ty-five per c nt. and an th r on hundr d. 

HE::IIITREll[JA HETER D N, RTIIElC. lE::lll'l'RE IIA. 

This p cie extr m ly abun ]ant in 
been taken by us outh f the central part 
Rock Riv r it has b n o-en rally found in 
de cription from Lak Ii higan c.lown. 

rth rn Illinoi , has not 
f the tat . orth of 
tr am and lake of all 

The o-ill -raker ar f w in numb r, but thi k, triangular, and 
rath r lon o- those on the po terior part of th arch being from a 
fourth to a third the 1 ngth of the filam nt . Th intestin i' 
contain c.l one and one-fourth times in the length of th head and 
body. 

Eio-hteen specimen were studied, suitably distributed as to time 
and place. A little mud was found in the stomach of one. nly 
about one-tenth of the food consisted of vegetation, chiefly flowers 
and eeds. Traces of filamentou Algre occurred in two f the 
pe imen . nivalve Mollusca were noticed i11 one, and in cts 

in twel e, amounting to more than a fourth of the ntire food. 
These wer chiefly larvre of Chironomus ( tw nty per cent.), 
ephemerid larvre occurring in but one. Crustacea were reckoned 
at fifty -eight per cent., all Entomo traca, with the xception of a 
·ingl Allorchestes dentata. About two-thirds of these wer 

lado era, the r mainder being Ostracoda and op poda. Roti­
f rs and Protozoa al o rarely occurred, the latt r including Centro­
pyxi and Difflugia. Five of the sp cimen had eaten Entomos­
traca only, and two other ninety per cent. r more. Only tw 
had derived more than half their food from vegetabl source . 

It will be seen that the peculiar fact with re pect t this species 
was th larg per cent. of Ent mo traca appropriat d. I find 
nothing in tb stru tur of th fi h to xplain this cir um tance, 
other than the som what unusual d v 1 pment f the gill-rak rs 
and the small iz of th spe 1es. The latter pr bably had mor 
to do with it than anythin else. It h uld be n t cl, h w v r, 
that nearly half the specimens wer d riv d fr m pla wh r 
Entomostraca w re x s iv ly abundant at th tim of th ir 

capture. 



86 The Food of the Srnaller Fresh- Water Pislies. 

SUMMARY OF THE GROUP. 

T~king now this group as a whole, we remark, first, the absence 
of mud mingled with their food, as related to the greatly dimin­
ished length of the alimentary canal. We have now also a 
decided predominance of animal food, which is about three-fourths 
of the entire amount, and note likewise the first occurrence of 
fishes. Although Mollusca occur in this group, it is in quantity 
too small to appear in the ratios. Insects make about half the 
food of all, nine per cent. being terrestrial forms. The larvre of 
N europtera are by far the most important insect species, and 
stand at twenty-five per cent. Entomostraca make a -fifth of the 
whole food, distributed among all the orders. The vegetation 
eaten was largely of a purely miscellaneous and incidental char­
acter, only about a third of it being derived from aquatic plants. 

GROUP IV. 

Intestine short; teeth hooked, without grinding surface. 

This gr.oup, organized more strictly for predatory purposes than 
any of the preceding, contains also the largest number of g~nera, 
embracing nine of those occurring in Illinois. It was not thought 
necessary to study all of these, and my dissections were confined 
to five of them, namely: to Minnilus, Ph,otogenis, Phenacobius, 
Semotilus and Ceratichthys. 

MINNIL us ATHERINOIDES, Raf. EMERALD MINNOW. 

This species is everywhere abundant in streams and lakes, but 
does not occur in ponds. It is most common northward, swarm­
ing in summer along the shores of Lake Michigan. 

The gill-rakers are short, triangular, and about one-fourth the 
length of the filaments; and the intestine is less than the length 
of the head and body. 

Eighteen specimens were studied, all from the northern half of 
the State. The food was almost strictly animal, but five per cent. 
consisting of vegetation, and this chiefly of accidental character, 
occurring in trivial ratios. Only a single specimen had taken 
about forty per cent. of its food from :filamentous Algre. A 
minute fish had been eaten by one of these minnows. Insects 



The Foocl of the maller Fte h - Water Fishe . 7 

made two-third of th food nearly two-third f th m b ing t r­
r trial. N ur terou larv, ' w r th prm i pal aq uati form , 
chi fly ·a e-worm an<l lan',' of ph m rid . 1'h ru ta a 
( twenty-tw per cent.) were all Entom tra 'a, ab ut tw -third 
of them ~lado ra, the r main l r p p tla. m no- th form r 
Bosmina and hydoru · wer r ogniz d, and Diapt mu among 
the latter. 

ix of thi species had eaten only in ect , and these made 
nin t3 per c nt. of th food of two others. n ha<l filled it elf 
with the larvre of Bibio ilbiJ nnis, at rre trial rub abundant in 
early pring. Three from P oria Lake, captur d in ct b r, had 
eaten ladocera only, nearly all a singl spe i , Bosmina lon­
girostris. 

PHOTOGENI AN ALO TANU , Grd. ILVER :B'r . 

Excessively abundant in streams f all sizes. 
The gill-rakers are short, triangular, about one-f urth of th 

length of the filaments. The inte tine is shorter than the head 
and body. 

Thirty-three specimens of this species wer examined. Tw -
thir ls of th food was insects, seven per cent. fi h s taken by 
thr e individuals, and on per cent. spiders, bringing the rati f 
animal food up to seventy-one per cent. Be id . th , a Limna~a 
was eaten by one, and traces of Cladocera and Cop poda occur in 
three. early half the · in cts wer terrestrial, rixa and neu­
ropterou larvre being the most important aquatic f rms. Th 
vegetabl food (twenty-nin .per ent.) was nearly all f terrestrial 
origin, about one-third consisting of Algre, b th £lam ntous anci 
unicellular, incluuin · pirogyra and GI ocystis. Se d , anthers 
and pollen of plants, and fragm nts of gra s-lik v g tati n were 
noticed. 

Eight of the specimens had taken only in cts, and in two other 
these amounted to ninety-five p r c nt. Two had fed up n 
terrestrial species only. Corixa mad ninety-five per cent. of the 
food of one. One had fed s 1 ly upon filamentous Alg , and 
ninety per cent. or more of the food of three oth rs consist d of 
vegetable structures in general. 



88 The Food of the Smaller F resh - Water Fishes. 

P HEN AC0BIUS . . 0PIFERUS, Cope. 

This species occurs not very abundantly throug hout the State, 
from Galena to extreme Southern Illinois. It has been taken by us 
almost invariably in swift and shallow streams. 

The mouth is small and inferior, provided with fleshy lips 
somewhat resembling a sucker's in form. The gill-rakers and 
pharyngeal teeth are as usual in this group and the intestine is 
contained once and a half in the length of the head and body. 

The nine specimens studied were from five localities, distributed 
from Galena to Union county. The food was almost purely insects, 
only two per cent. being unrecognized vegetation. Seventy-six per 
cent. consisted solely of Chironomus larvre, and six per cent. of 
case-worms. Adult chironomids, taken by two of the specimens, 
amounted to two per cent. A few Cyclops found in a single 
specimen were the only Crustacea eaten by these fishes. 

The peculiar character of this food, almost precisely that of a 
darter, is evidently related to the habitat of the fish.* 

SEMOTILUS C0RP0RALis, Mitch. CHUB. 

This is a widely distributed and very abundant fish, perhaps the 
commonest species in the small creeks; but is less abundant in 
lakes and ponds. 

The head and mouth are unusually large for a minnow; the 

intestine is six-sevenths the length of the head and body; and the 
gill-rakers are of the usual form. 

T wenty-two specimens, from widely separated localities, give a 
ra tio of seventy-six per cent. of ani~al food, four per cent. being 
fi shes (partly Cyprinidre ), thirteen per cent. veg etation, and three 
per cent. worms. Insects make a little over half the whole, about 
one-half of them terrestrial. N o Chironomus larvre were found 
in the food of these fishes. Of neuropterous larvre only a trace 
occurred, aquatic Coleoptera were noted in two, and Corixa in one. 
Grasshoppers (Acrididre) made ten per cent. of the whole and were 
eaten by three of the specimens. Five had t aken crawfishes, 
which made twelve per cent. of the entire food. No Entomostraca 
were noted, with the exception of one per cent. of Cyclops 

*For a discussion of this matter, see Bulletin 3 of thi s series, p. 25. 



The Food of the mall r Fre h- TVat r Fishe . . 

oc 'U1T111g in two f the p mm n . um r u xampl f 
Gonliu w re found in two, an 1 wer r k n l at thr p r nt. 
of th f cl~<- The v aetable fo d (tw nty-f ur p r nt.) wa half 
_-\lo-,l·, th' r maind r mi llan u v etabl l bri . 

Eight had eaten only in ct , two havin fille l th m 1 v with 
oTa hopp r . Thr e fr m a prairi tr am n ar ormal had tak n 

onl crawfi h , whil f f ur p im ns aptur <l in J\I •L an 
County in July filarnentou Alg.. corn po d ninety-four p r ent. 
of th food. 

'1ERATI IITIIY BI ,.-UTT.A.TU,, Kirt. HoR.i: ED CHUB. 

Thi 1 verywhere abundant northward, chi fly, lik 
m tilu m th maller tr ams, but pref 1Ting swifter , at r . 

We hav n t taken it, how v r, outh of th c nt r of th tat . 
It differ from th prec ling memb r. of th group by th 

great r length of its alimentary canal, which con iderably ex ed 
the head aml body, the latt r b ing contain d in the int tin 
about one and on -fourth tirn s. The gill-rak r are n t p uliar. 

Thirteen pecimens from North rn and ntral Illinoi · had 
d riv d le s than half their food from the animal kin <lorn. Only 
about one-fourth of it con iste I of ins ct ·, larg ly as -w rm and 
other neuropterou larv< , another fourth b ing Crustacean 

( rawfi be ) eaten, how ver, by only two f th specimens. The 
vegetable fool (fifty-four p r cent.) wa ab ut equally divid cl 
between fi.lamentou · Algre and see ls of etaria and oth r ara -
like plants . 

.r otwith tan ling th mall ratio of ins t fiaur l ut, it 1s 
worthy f not that two specim n out of four aptured in a r k 

111 epternber ha l aten nly in ects, chiefly a -w rm , , hil 
th c mposed nin ty-fi ,- , p ' r ent. of th foo<l of another. ~ 

the inte. tines of the e fishes contained a consi<l rable quantity of 

grav 1, it i ... evicl nt that they hacl f l upon th bottom in rath r 
swift water. n th th r hand, two sp cim n had l riv d all th ir 
food from veg tabl our e and thr nth 'r ba l ,at n ighLy 
p r nt. r more of v g tation. Th xtraordinary amount of 
v getation in the fo <l of thi fi h i po sibly r lat cl to iii 
increas cl lenath of the alimentary anal. ::-, 

:,'These were not from the same specim ns a· tho e containing th 
grns hoppers. 



90 The Food of the Smaller Fresh- Waler Fishes. 

SUMMARY FOR, THE GROUI->. 

Nin ty-fiv ·p imens of Group IV examined, representing 
five genera, had derived about three-fourths of their food fr m the 
animal kingtlorn, . three per cent. of it b ing fishes, sixty-one per 
cent. ins cts, one per cent. A rachnida, and eleven per cent. Crusta­
cea. One-third of t he insects and spiders belong to terrestrial 
species. Chironomus larvre are among the most important aquatic 
el men ts, amounting to sixteen per cent.; neuropterous larvre 
coming next (eleven per cent.). About two-thirds of the crusta­
ceans were erawfishes, the remainder being Claclocera and Copep­
oda. The v getation (nearly one-fourth of the entire food) was 
chiefly of miscellaneous origin, nine per cent. only being recog­
nizable as of aquatic forms. This was almost entirely filamentous 
Algre . 

Concerning this fourth group it may consequently be said, 
roughly, that the food consists of insects, crustaceans, and vegeta­
ble debris, about two-thirds of it the first, one-fourth of it the last, 
and one tenth, the other. 

Summary.for the Family. 

If we regard the two hundred and fourteen specimens of 
fourteen genera which I have studied, as fairly representative of 
the family Cyprinidre, and strike a separate balance of their food, 
we shall find that about thirty per cent. of the contents of the 
alimentary canal consists of mud; that one-half of it, or a little less, 
is animal matter, and that vegetation amounts to about one-fourth. 
Insects make one-third of the entire food, about ten per cent. 
being terrestrial species, eight per cent. Cbironomus larvre, and an 
equal number larvre of Neuroptera. Of aquatic Coleoptera we 
have only-a trace, and of aquatic H emiptera (Corixa), but one per 
cent. Crustacea stand at ten per cent., nearly half of them 
Cladocera, Entomostraca as a whole amounting to about three­
fourths of the crustacean ratio. Fishes are only two per cent., and 
mollusks less than one. N early half the vegetable food consists 
of Algre (chiefly filamentous forms), the remainder being miscella­
neous structures, derived from a· great variety of plants, mostly 
terrestrial. 



The Food of the maller F,.r, h- JVat ,. Fi he . 1 

ummino- up, in aw rd, th hara t ri Li f th f od of th fami -
ly a thu indicat d, w may a that about on -half of it · 

f animal ub tan n -thirtl h ing in ,t , an l on '-thirJ f 
th e of t rr trial p i , and t n p r 'nt. b in · ru t.a an · 
that no-fourth onsist d f v o- tati n, about qually a uatic an l 
t rr' trial and that th r maind r i mud, pr bably ntainino-
m re or 1 fluid r ani matter. 

CoMPARI F THE GR p 

It will be r m mber d that th gr ups w r ba d upon liff r-
n in the tructur r lating to th appr priation an 1 ma tica-

ti n of food. It i con equ ntly from a mpari on f th rati 
f th s groups that w hall d rive th m t int r stino- fa t 

r 'lating to th" c rre pond n of food and stru tur . Th rn t 
on pi u u r sult is th great prepond ranc of mud in th 

int tiu f th fi hes of th fir t roup, characterized by an extra-
onlinarily longat inte tine, and by pharyng al t th d titut 
of hook and provided with a broad a-rinding urfa e. H re, a 
alr ady noted, mud, and, and gravel amount d to about thr -
fourth of the matter ingested, while in the third and fourth group 
only trivial and accidental quantities occurr <1. In th c nd 
aroup, on the oth r hand, with inte tin s interrn diat in l ngth 
mud was still abundant, but much l s so than in th first, av r­
aging 1 s than half the whole. If w x lud this indig stibl, 
matter, however, we hall find the fir t gr up still forth r li tin­
o-ui h d by the predomina.nc of vegetation a compar d with 
animal matt r, the latt r b ing only about n -third the f rmcr, 
while in roups III and IV, n th other hantl, v g 'tati n 
amount to about one-third th animal f od. Th o-roup la t 
mentioned, distin ui hed from ach th r a · th y ar , only by the 
presenc of a ma ticat ry surfa e on the pharyu al t th in th 
first, and its absence in the econd, differ ar ely at all in th ir 
g neral fo d baracters, and this tructural f atur s cm th ref re 
to be of little significance. In b th the adimal rati am unt · t 
sev nty-five p r cent., and v getation tands in ach at twcnty­
fiv ; whil insects are r pectively fifty and si ty-on . It i tru 
that we fin neur pt rous larvre greatly pr dominant in th fir 

roup, makino· n -f urth f th ir f d, ancl hiron mus htrv, 
in the se nd amounting t sixte n p r ent. Th , nd of 



92 The Food of the Smaller Fre h- Water Fi,shes. 

th fa t we find upon analysis to be evidently due to Ph naco­
biu , by whi h g enus nearly all the Chironomus larvre were taken; 
and thi , as already shown, is explained not by any structural 
f ature, but by its peculiar habitat; and when ·we note that· 
aquatic larvre together amount in Group III to twenty-five per 
cent., and in Group IV to twenty-seven, we see that the signifi­
cance of the difference mentioned disappears. A similar explana­
tion is found of the difference in the ratios of Entomostraca,­
that of the first group amounting to twenty per cent. and that of 
the second only to four. An examination of the tables shows that 
this predominance in the group first mentioned is nearly all tracea­
ble to Hemitremi-a, a very small fish with rather elongate gill-rakers. 

The importance of these gill structures is still more clearly 
indicated, as already noticed, by the difference between N otemi­
gonus and Chrosomus of the second group, and clearly far out­
weighs the structure of the teeth as an indication of the food 
habits of the fish. 

The general conclusions reached may be thus briefly stated: 
An extraordinarily elongate intestine indicates the limophagous 
habit, rather than an especial preference for vegetable food. The 
length or number of the gill-rakers has · much to do with the 
abundance of Entomostraca and other minute animal forms in the 
food of the fish, while the presence or absence of the terminai 
hook or the masticatory ·surface to the pharyngeal teeth is not thus 
far shown to have any sensible influence upon the general average 
of the food. Finally, a species may depart widely in food char­
acters from those more nearly allied to 'it in structure, if its 
favorite haunts are peculiar. 



The Food of the m,aller Fresh- Wat t F i !tes. 

T .\BLE 01? 1~ OD: APHREDODERID ,R TO U I BRID ,11:. 

I 
N 11Blrn Of' SPE IME A ND RATIO ~ 

K[XOS OF ~ _ 0. WHICH EACU ELEMENT OF .i'' OOD WAS 
. FO ND . ________ _,_ ___ _ 

ANll\lAL 1.t' OOL> . .... .. . . ...... .. .. .. .. ·I .991.00 .·. 7·5· 1..00
01 

.• · .1. *90!· ··63··· 1· .· o·o· /0 ' .. ·5·9· 
l. FISHE .. .. .. . . .. . • . .. .. . . .. .. . .. .. .02 .27 

1i!:1~l~8
: .~~: ::: ·: ::::::::::.::::::::::::::.1:.:·:·:· ···· ·01 

·8~ ·8~, ·: : ·i~ ·s~ 
u1. IN ECT ..... . ...................... 91 .44 ::~i ]~ ·: :~7 ·:1al· :i._.* .. -: ,m -: i: 
Aquati · larvre ..... .. .. .. .... ... .. ... . 0 .36 .. . , ... , . ... .... .... .. . .. 

1 
. .. 

1. Ilym noptera. ...... . . . .. .. .. . . .. . . .. .. .. .. . .. . .01 .04 0 I .O~ .. .. .05 ... 
2. Dipt 1·a . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 l .01 ' .43 .46 I .1 .21 .07 ·• .14 * 
Terre trial . .. . .. .. . .. .. .. .. .. . . .. .. . .. .. . . . .. . .30 .01 .02\ .... 

1 
.. • 01 ... . 

~~i~~ti~~tct\e.·.· :·:::::::.·.·· .. ··.·.:.·.·.· ·.· .. ·.:· ....... , ·· ·11 ·2~ .... . 01 ...... . 01 .. . .. . . .. .. .. .~o .01 .01 . .. .. .. t I .. . 
Aq,ua.ti~ (larvm) ..... .. ....... .. ...... . . ~43 ·.·.·. · .. .. 3.7_, .. 0.5 . . ·. 0·2·: 1··.·.·_ ·.·. ·.· . . 01 ... . 

nlic1tlm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , I 
·r~fi~f~:!~~·.~· .: ·:·:·:·:·<::.:.::.:.::.:.:: :::><:1 :gi .... ji ·: 05 ·:o~ ·::: :::: :::: ·:~i 

3. Col optera . .... . ....... . ~.... ..... .... .11 06 17 08 
T rr trial ............................... 11 · . : .. j. ::. :::: .: .. 
Aqua.ti larva~........... .. .. ... .. . .. . .. .03 .0 ... ..... . 04 
Hy<lrophilid ro . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0 . . . .03 

Philhydrn .. .. . .. . .. . .. . .. .. . .. . .031.04 .. . 02 
4. ffemipter a .. .. ......... .. .... .. . ........ . 02 .. . .. .. .01 .02 .17 .0 * .09 .03 
Terre trial.. .... . ....... .. . .. .. . .. .. .. .. . .01 .02 .05 .05 .. .. .04 .. 
Aquatic....................... .. ... . .. .... . . . . .11 .01 * 04

1 

... . 

Corixa . .. .. . .. .. .. . .. .. . .. .. .. . .. . .. .02 . ... 

1

.... . .10 .. .. * .03 .. . . 
5. Yeuroptera (lan·::c) . . . . . . . . .. .. . . .. .. . .25 . . . .. . .06 11 .03 .01 . . . . .05

11 
.. . 

Ephemerid:e .. ........... . . . ..... . . . .. .. .. 14 .... .. ····J .11 ----J---- .... . 0-l ... . 
Palin a-enia .......... ................... . 07 .. .. ...................... ·I .. .. 
dona ta . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0G . . . . .o· . . . . . . .01 .. 

grion .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . · 1 ·0l 03

1 

.. . .. .01 
Libellulidre. .. .. . .. . .. .. .. .. .. .. .. .. .. .11 .. .. . . .. .. .. .t .. ·1 · .... _· 
L ptoceridrc..... .. .. . . .. . .. . .. .. .. .. 1-- .. .. .. .. . .01 ... 
G Thysanurri (Poclura)...... . . . . . . . . . . . · • • • I 1' 
IV. ARACHNIDA .. .. . .. . .... .. .. .. • .. . .. .. ..... , .01 1 .03 .02 .03 . ... .02 "' 
Terre trial.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .01 1 .03 02 .03 .0:. 
IIydntchnithe .. ........ ....... ...... .. ·.· 0·4· 1· .2·9· 1·· .. 3·0· -t.40 -t -- 0·6·1 ··0.•> * ... -t 1, 
V. CRU TACE.\. .. .. . .. . . .. .. .. .. .. .. .. .. .. - .21 ~ .10, .13 
1. Aniphip oda . .. .. ....... .... .... . ..... 03 I .. . .13 * 02 ..... 05 .03 
2. I sopoda (A ellns) ........ .. .. ......... 01 .2\J .. . ... .. 
3. Otadocer·a ............................. I ....... · 1 ·28 .24 01 .02 t • .01 .06 
Jhphn.iitl ai . ......... .. .. .. ....... ... .... . ·· 1' ..... 14 .23 1 ..... Ol l ........... 1 ··· 

Lyn.·e 1<h . . ... ........ . . . .... .. . . . ... ....... J.. .. .14 .01 1 .01 t .... * ...... .. 
4. 08tracoda . .... . ... ... . ... .. . • ........... -t . . . . .01 . . . . .07 .02 .... . . 03 .04 
5. Oopepoda. . . . . . . . . ... . , . • . . . . . . . . + .01 .lG 1-- .. .02

1

.01 .. . .011 ... . ,:r. \'ERll:ES(Ohretop od a) . ..... .......... 1.02 ......... .. .... . .. ..... .. .... .. .. 
\IL Prot zoa .......... .. .. . .. ... ....... .... 1 . ....... 1.... ... t .... t .. .. 
VEGETABLEF OD .. ................... 01 . .... 25 1 .... . l!l .10

1
.37 .17 .41 

t ii~1f~e~~:::::::::·:::.::::::::::::>::: ·~~1 , :::, ·:~~ ::: :: :~:, :~: :gf ::: :~! :~3 



94 The Food of tlie Smalle1· F1·esli - Water Fishes. 

TABLE OF FOOD OF CYPRINID.lE. 

--·-- ------ l--l--1--1--l--11--1---1--11--1---1--1--1--1 - 1- -1---1--1--1- _ 

No. of :specimens ... 9 4 9 8 30 25 3 28 1 17 5 21 18 61 18 33 9 22 13 95 

K I NDS OF FOOD. NUMBER OF SPEOIMENS AND .RATIOS IN W B IOB EACH ELE MENT OF FOOD WAS FOUND. 

A NIM .A.L .1!'00D .... ...... 27 ..... ... 07 .35 t .18 .69 .76 .62 .87 .73 .95 .71 .98 .76 .46 .'77 .48 
1. FISHES . . .. . .. .. .. . . . .. .. .. .. . . . .. . . . . .. . . .. .. .. .. .03 . .. . .14 .. . .04 .03 .. .. .. .. .04.... .. . . .tl 
I I . l\! OLLUSC A......... .. .. . . . . .. .. . . .. . .14 .. .. .07 .01 .. .. . .. . t t .. .. t .... ......... ..... . 
U1iivavves. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14 . . . . .07 . . . . . . . . t t . . . . t . . . . . . . . . . . . . . . . 
Bivavves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 01 . . . . . . . . . . . + . . . . . . . . . . . . . . . . . . . . ... 
I I I. INSECTS . . ...... . . t .25 t ... .. 06 .06 .. ... 03 .51 .66 .45 .29 .48 .67 .63 .98 .156 .24 .61 .8' 
'I'errestrial..... . .. . . .. .. . .. .. .. .. .. .. .. .. .. .. .. .. .. . . .. . .. . . .03 .. .. .01 .02 * .. .. .. .. .. .. .OJ I .10 
Aquatic.. ...... .. . . . .. . . .. .. .. .. . .. . . .. .. .. .. . .. . .. .. .... .. . .. . .02 t t . .. . .01 .. .. .12 .03 .03 ... 
1. Hynienoptera ....... .. .. .. .. . .. .. . .. .. . . .. .. . .. . .. .. .. .. .02 .. .. .01 .05 .04 .. . 10 .. .. .04 .. 
2. Lepidopter a .... .... .. .. . 15 ..... ... 04 .03 .. .. .01 .. ..... t ... t .01 .05 ..... 01 .03 .02 . 
3 . .Diptera . .. ... ....... t .10 ...... . 02 t .. .. t .03 .05 .04 .24 .09 .14 .26 .'78 .08 .01 .25 .. . 
Terrestrial ... ... .. .. .. .. .. .. .. .. . . . . . .. . .. .. .. .. .. .. . .. . . .. . .. . . .01 + .11 .18 02 t ..... 06 ... 

Chironomid::e .. .. .. . .. .. .. .. .. .. . . .. .. .. . .. . .. .. . .. . . .. . .. .. . .. . .01 t .. .. .. . . .02 .... .. ........ . 
Aquatic (larv::e) .. .. t .. .. . . .. .. .. t + .... + .03 .... ... .. 20 .06 .02 .06 .'76 ..... 01 .17 .. 

UhiJ.·onomus .. .. . .. . . t ............ t 'I' .. . + .03 . . .. .... . 20 .06 ..... 03 .76 ..... 01 .16 08 
Sim11liun1 .. .. .. . .. . .. .. . . .. .. .. .. . . .. . . .. .. . .. . .. .. .. . .. . . .. . .. .. . .. .02 .02 ........ ......... .. 

4. Coleop tera ...... . .. .... . •.. . .. . . . . . . .. .. .02 .. .. .01 .18 .. .. .06 .. .. .06 .13 .02 .. .10 01 .05 ... 
Terrestrial . ...... . .. . .. . .. . . .. . .. . . .. . .02 ... . 01 .18 .. ... 05 .... . 06 .13 .01 .... . 05 .01 .04 . .. 

Carabid::e.. .. .. .. .. . . . . .. .. . . .. .. .. .. . .. . .. . . .. . .. .. . .. . .. .. .. .. . .. . .. .. . 04 .. . . .. . . 01 .. . . .01 j · .. 
Aquatic ... ... .. . . ..... . .... ..... . . . . .. ... . ... . . ... . . .... . . . ... . 01 . .. . t .. . . . . . . .. . . 03 ... . . 01 t 

Hali plus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .02 . . . . .01 .. . 
(}yrinidre (larvte ). .. .. .. .. . . .. .. .. . . .. .. .. . .. .. .. .. .. .. .. .. .01 . .. . t .. . .. .. .. .. . .. . .. .. .. .. .. . 
Hydrophilicl.~ ....... .. .. .. . . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . . .. . .. .. . .. . . .. . .. . .. .. .01 .. .. t .. .. 

5. Herni,pte1•a .. . . . .. .. .. . . .. . . .. . . .. .. . .. .01 .. . . .01 .01 . . . 02 .... + .11 .10 . .. . .03 . .. . .05 .. . 
'I'e r1·estrial .. .... . .. . . . .. . .. .. .. . .. . . .. . . . . .. .. .. . .. . .. . . .. t .... t .05 .01 .. . .. .. .. . 01 . 
Aquatic..... .. . .. .. . .. .. .. . . .. . . .. .. . .. .01 .. .. 01 .01 .. . . .01 .. .. .01 .05 .08 .. . .03 .. .. .03 .01 

<Jor ixa . .. .. . .. .. . .. . .. . . .. . . .. .. .. .. . .. . .. .. .. .. .. .. .. .. . .. .01 .. . .01 .. .. .08 .. .. .03 . .. . .02, . .. 
6. Orthoptera . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ... .. . . ·.1·7· . ·.1·0· . ·.1·4· _._ 1_2_ .. ·1·6· .. 0121, ... 08. 

1. Neuroptera .. ... ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28 .58 .10 .03 .25 
Larvre ................ ........ .... .. .... .... .. .. .... ...... .... . 04 . .. .. 01 .. .. .01 .08 .... 03 .02 .. .. 
P tl })00. . . . . . . . . . . . . . . . . . . • ' . . . . . . ' . . . .. ' . . . . . . . . . . ' . . . . . . . . . . . . . . . . . . . . . . . . '03 ' . . . . . . . . . . . . 01 .. 
Ephemerid::e ... ....... .. . . . .. . .. . . .. . . .. .. .. .. .. .. .. . .28 .48 .06 .03 .21 .10 .01 .. .. .. .. .01 .02 .. ... 

0 , : Phryganeidre .. .. . .. .. .. .. .. . . .. .. .. .. . .. . .. . . .. . .. .. .. .. .10 .. .. .. .. .03 .07 . 5 .06 .... .12 .06 .. 
I V. ARACHNI DA. .. . .. . . .. . . .. . .. .. . .. t . .. . .. ... .. ... .. t t f .02 .01 . . ........ . 011 . 
V. CRUSTACEA ........ ... .. t ... . t .15 t .08 .13 .10 .03 .58 .21 .22 f -t .13 .22 .11 10 
1 . .Decapoda (Craw.fish) . .. . .. .. . .. . . .. . .. .. .. . .. .. . .. . .. . . . .. .. . . .. .. .. .. .. .. . . .. .. .. .12 .22 ._07_

1 

.... 
2. Arn,ph:ipoda.. . ..... . . . .. . .. . . .. . .. . . .. . .. .. .. .. .. .. .. . . .. . .03 .01 .01 .. . . . ...... . ... .. .. 
3. Cladocera .. .. . .. . .. . .. . .. . . . .. . . . .. .. .. .10 t .05 .01 .. .. t .36 .09 .15 t .. .. . . .. ..... 03 .0& 
Sididre (Daphnel la)... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .01 t . . . . . . . . . . . . . . . . . . . . . . . . .. . 
Daph niid£e. . .. .. .. .. .. .. . .. .. .. .. .. .. . ... .10 .... . 05 ... . .. .... . t + .12 t . ....... ... . 02 .. .. 
Lvnceidre .. . .. .. .. .. .. .. .. .. . . .. . . . .. .. .. * .. .. * .01 .. .. t .35 .09 + t .... ...... .. t .. 
4,- Ostracoda .. .. .. . .. . .. . . ... + .... t * .... "' .12 .... t . . 04 .04 .. . . .. . .. .. .. .. .. .. .. .. .01 
5. Copepoda,..... . .. . . .. . .. .. . .. . .. .. .. .. .05 .. .. .03 . .. . .10.. .. .17 .07 .07 t t .01 .. . . .01 .II 
VI . VERMES .. .. .. .. .. . .. . .02 .. .. .. .. .01 .' ..... .. .... .. ...... t t t .. .. . .. . .. .. .03 .. .. .01 ... . 
Lnmbriculus .......... .. . .. .. .. .. .. .. . .. . .. . . .. . .. .. .. .. .. . . t .. .. t .. .. .. .... . ............... . 
Naidre . . . . ... .... . .. . . . . . . . . .02 . . . . . . . . .01 ... ... . . . ... .... .............. ... . . .... . .. . ............. . .. . 
Gord ins .. .. .. .. .. .. .. . .. .. .. .. .. .. . .. . .. .. . . . .. .. . .. . .. .. .. .. .. .. .. . .. .. .. .. .. . . .. .. .03 .. .. .01 .. .. 
Rotifera . . .. .. . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . .. . . .. . .. . .. .. .. .. + + .............. .. .... .. .... .. 
VII. P ROTOZOA .. . .. . t ........... t . .. . .. .. .. .. .. , .. .. , .. . t t · .. · .. .. · .. · .............. .. 
VEGETABLE FOOD .20 .01 .20 .25 .18 .50 .13 .31 .31 .24 .38 .11 .26 .05 .29 .02 .24 .54 .23 .t-8 
Miscellaneous . ....... . . 02 t .15 . .. . 09 .21 .02 .11 .10 .01 .05 .03 .05 .01 .06 .02 .10 .02 .04 .. . 
1. F111rigi . . . . .. . .... .... .. . . ..... . .. T t .. t t . .. ..... t . ... t ..... .... . . .... .... .... .. .. . 
2 . ..dlgce .. ........ . .... . 18 .01 .05 .25 .09 .19 .09 .14 .11 .... . 12 .01 .05 .01 .09 .... . 12 .23 .09 .10 
MUD AND GRAVEL .75 .72 .80 .'75 .75 .15 .87 .51 · t ........ 02 .01 ........ t ........ t 29 

' 

• 



ERRATA. 

Page 6, line 12 from bottom; page 8, line 15; page 11, line 2; 
for Cyclniclce, read Pentatomidce._ 

Page 17, line 9, before Vireo; omit ancl. 

Page 23, above ARACHNIDA, for Cyclnidce, read P entatomiclce. 

Pages 25 and 27, above Orthoptera, for Cyclniclce, read P enta-
tomidce. 

Page 28, lines 2 and 8, for Graphorhinus vados1ts, read Epi-
cce1·us imbrricatus. · 

Page 64, under Hemiptera, for Siplwnophora granarice, read 
Aphis maidis. 

Page 69, line 5 from bottom, for jresh-wate1·, read local. 

Page 78, line 1, after all, insert the. 

Page 82, line 7, for cha1·acte1·, read charctcte1·s. 

Page 91, line 5, for consisted, read consists. 

Page 92, line 2 from bottom, for more, read most. 

Page 97, line 11, for f01·y-six , read f01·ty-six . 

Page 99, line 2, for witn, read with. 

Page 101, lines 12 and 13 from bottom, for stritcture, read 
structitres. 

Page 105, line 23, for aeration, read ae1·cttion .