Bulletin


STATE OF ILLINOIS

DEPARTMENT OF REGISTRATION AND EDUCATION

DIVISION OF THE

NATURAL HISTORY SURVEY
STEPHEN A. FORBES. Chef

Vol. XVII. BULLETIN Article X.

An Account of Changes in the

Earthworm Fauna of Illinois
AND A

Description of One New Species

BY

FRANK SMITH

PRINTED BY AUTHORITY OF THE STATE OF ILLINOIS

URBANA, ILLINOIS

August. 1928



STATE OF ILLINOia

DEPARTAIENT OF REGISTRATION AND EDUCATION

A. M. SiiKLTON, Director

BOARD OF

NATURAL RESOURCES AND CONSERVATION

A. M. Shelton, Chavman

WiiJ.iAJi Trelease, Biology

Heis'KY C. Cowles, Forestry

Edson S. Bastin, Geology

William A. Noyes, Chemistry

John- W. Alvord, Engineering

Charles M. Thompson, Representing

the President of the University of

Illinois

THE NATURAL HISTORY SURVEY DIVISION

Stephen A. Forties, Chief

ScHXEPP & Barnes. Pri.vters

Springfield. Ill

1923



Volume XVH Article X

AN ACCOUNT OF CHANGES IN THE
EARTHWORM P^AUNA OF ILLINOIS

AND A DESCRIPTION OF
ONE NEW SPECIES*

Frank Smith

The contents of this paper include additions to the list of species

previously recorded from Illinois and also furnish evidence of obvious
changes in the earthworm fauna of one locality which are probably simi-

lar to changes taking place in other parts of the state. The tendency is

towards an increasing domination of European species and a correspond-
ing decrease in the abundance of some indigenous forms. There are

various records of similar modifications of the earthworm fauna in other

parts of the world in which Europeans have settled and in which the

European species of Lumbricid.\e have to a greater or less extent re-

])laced the indigenous species.

Recent additions to the former lists of European species found in

the state include Hclodrilus vcnctus hortcnsis ( Michaclsen ) , H. clilo-

roticiis (Savigny), H. octacdnis (Savigny), and Liiiiibriais rnhcUus
Hoffmeister. Additions to the list of indigenous species include Hclodri-

lus bcddardi (Michaelsen) and H. heimhurgeri n. sp.

During a period of over 30 years (1893-1927) the writer has been
interested in Illinois earthworms and their distribution, partly because

of their utilization in some of his instructional work and partly because
of using them as objects of research leading to the publication of several

papers on the subject. In connection with these activities numerous col-

lecting and observation trips have been made in the vicinity of the Uni-
versity of Illinois in order to obtain sjiecimens of the various kinds repre-

sented and, incidentally, to learn something of their relative numbers and
the kinds of situations in which representatives of the various species are

most abundant. A comparison of the results of such trips made in earlier

years of that period and those near its close shows that some marked
changes have occurred. Some kinds found infrequently or not at all in

the earlier years have become abundant in some areas in which there

has been a corresponding decrease in other species. Increasing irregu-

larities of distribution have been apparent which are presumably due to

increased numbers of introduced forms which have not as yet had time
to become abundant except in restricted areas.

* Contributions from the Zoological Laljoi-atory of the University of Illinois
No. 322.

[347]



34S Ii.r.ixuis NATruAi. HisToitv SriivioY Bi'Llktin

UPLAND-SOIL SPECIES
The collecting and observation trips which involved ordinary npland-

soil species have mostly been made immediately after rainfalls when
large numbers of individuals of some species were crawling about on the
surface or were sheltered under debris of various kinds and especially
likely to be found on the sidewalks and along the curbing of paved streets.

Actual digging for such forms has been restricted to small areas. The
lack in the earlier years of a knowledge of the changes in the fauna which
were to take place resulted in a failure to make records of dates and of
luany numerical data which, if available, would have been very useful in

the preparation of the present paper.

The three species of Lumbricidae, listed under other names by Car-
man (1888) as frequent or abundant in Champaign, Illinois, were Hclo-
drilus foetidus (Savigny), hi. roscus (Savigny) and H. caUtjinosus trap-

czoidcs (Duges). They were fotmd in similar abundance throughout the

whole period of 1893-1927. Octolasiinu lacfcimi (Orley) was also of

frequent occurrence throughout the same period, though not listed by
Garman. H. lougicinctiis Smith and Gittins (1915) was found in limited

numbers in a woodland of the vicinity of Urbana in 1901 and in consid-

erable numbers in parkings and lawns of the city itself in 1910-1915, but

has not been noticed since the latter date. The most interesting feature

in the relations of the earthworms of the upland-soil localities that re-

ceived attention, centered in the relations between Diphcardia commums
Garman (1888) and Limibricns tcrrcstris Linnaeus, Miiller. Carman's
description of the former species was based on material from the Cham-
paign-Urbana region, and he states : "Hundreds were seen this spring

in this locality, migrating during showers of rain." The same statement

has been equally applicable to this species during the period 1893-1927,

with the exceptions noted in certain following statements.

The actual time of the first arrival of Luinhricus tcrrcstris in Illinois

is very uncertain. Garman (1888) and Michaelsen (1900) in their lists

of North American Oligochaeta refer to Eisen's (187-1) record of its

occurrence in "New England'' but have no record farther west. The
Motmt Lebanon, New England, of Eisen's record was actually in the

eastern part of New York. The first definite record for Illinois is that

of the writer published in 1900 and based on specimens found still earlier.

The exact date is not known, but it was certainly before 1898 and prob-

ably about 1896 that a few specimens were seen by the writer in a re-

stricted locality in Champaign, crawling about during a rain storm. About
the same date a workman engaged in digging a trench in an artificially

forested area on the LTniversity campus ( locally known as the Arboretum

)

found and gave to the writer a few specimens. These were the basis for

the record mentioned above. During this period and for several years
subsequently, it was necessary to send to dealers elsewhere for specimens
needed for class work. Then came a time, not far from 1905, when
specimens were sufficiently abundant in the Arboretum to meet some of

the needs for material, but they had not spread in any appreciable num-



EARTiiwoRii Fauna of Illixois 349

bers to other areas. Subsequently, the area within a few blocks of the
campus became abundantly stocked with them, while specimens of Diplo-
cardia coinniiinis became correspondingly infrequent.

In the forenoon of ]klarch 19, 1927, following a rainy night, the
writer traveled along the streets bordering an area of about one-half
mile square adjacent to the east side of the campus in Urbana and found
Lumbriciis tcrrcstris abundant in the streets bordering all of the 24 city

blocks involved, while the total number of specimens of Dif^locardia com-
ininiis seen was but 19, or an average of less than one per block—a marked
contrast to conditions existing in the same region in earlier times when
D. coiinuKiiis was abundant throughout and L. tcrrcstris was rarely seen.

A trip on the following day through the area lying still farther east re-

sulted in finding that D. coiiiiniiiiis was still abundant in a good deal of

the territory covered and that L. tcrrcstris was abundant in only a few
detached areas. Xo noticeable difference was found in the relative num-
bers of smaller introduced European forms, such as Octolasiiiiii lactcuiii,

Hclodrilus rosciis and H. caligiiiosus traf>ccoidcs. which were still abund-
ant in both of the localities examined. The area in Champaign into which
L. tcrrcstris has extended its distribution has also greatly increased in

recent years.

WOODLAXD SPECIES

Xo observations have been made which would provide information

concerning changes in relative abtmdance of the species that are more
commonly represented in decaying tree trunks, under logs, and in masses

of decaying leaves. Hclodrilus gicsclcri liciiipcli Smith (1915), H. sctcki

Smith and Gittins (1915), and //. tenuis (Eisen) (ISTi) are such forms,

and the writer is imaware of any notable changes having taken place

during the past 30 years in their relative numbers, or of the appearance

in such locations in recent years of introduced forms not previously

found there.

STREAM-BAXK SPECIES

The stream which has been most easily accessible and from which
most of the collections of stream-bank species have been obtained, is

locally known as the Boneyard Branch of Salt Fork. It is a small stream,

but a few yards wide, which originates a short distance north of Cham-
paign and flows south through the northern part of that city and then

east through the eastern part and through the city of Urbana, which lies

adjacent, and then joins the Salt Fork in the outskirts of the latter city.

Its course extends across the University campus in the western part of

Urbana. During the period 1893-192T there have been extensive changes
in the character of the water content and hence in the faima contained.

Increasing sewage contamination, due to increasing population and inade-
quate sewage disposal equipment in the two cities, of which it furnished
the principal drainage outlet, gradually led to the elimination of all of its

fauna except that which could exist under conditions similar to those of
an open sewer. The earthworm fauna of the banks has necessarily been



350 Ilunois Natikal Histoky Survev Bt i.i.f.tix

influenced by these changes. Such conditions reached a maximum at
about the time (1922-1U23) that J. L, Hyatt, a graduate assistant, made
an extensive series of collections of the earthworms inhabiting the soil

in the banks of the stream in various parts of its course. Since that time
the installation of a more adequate sewerage system and of a modern and
eflicient sewage-disposal plant has greatly altered the conditions, and
resulting changes in the fauna are already in progress. During the time
of Mr. Hyatt's collecting activities there was great diversity in the degree
of sewage contamination in different parts of the course of the stream.
In the part lying north of Champaign and in the northern outskirts there

was but little. In progressing down stream an observer would find con-
tamination from the few factories, the streets, and other sources becom-
ing inore and more evident, and the waters w-ere already laden with foul

material before the eastern limits of Champaign w-ere reached. Still

further additions were made in its course through the University campus
and Urbana.

A study of the earthworms collected from the banks of the stream

in various locations showed correlated changes in the relative abundance
of the representatives of the different species of earthworms. Certain

indigenous species and most of the species common in the upland-soil

regions were found in much greater numbers in the places of least con-

tamination, and certain other introduced species reached their maximum
abundance where contamination was very pronounced. Most of the com-
mon upland species were represented in at least small numbers, and in

addition about a half-dozen other species were represented which have

not been found in the upland-soil locations. A very decided lack of uni-

formity was found in collections made from different localities even when
the conditions and degrees of contamination seemed similar. Some species

had a rather limited area of distribution, indicating a relatively recent

introduction into the region.

The specimens collected were obtained by digging them from the soil

of the banks of the stream, and they were then taken to the laboratory

and fixed in a well-extended condition. The specimens were all pre-

served for the sake of greater certainty in identification and also with a

view to their use in other ways, including a search for abnormal speci-

mens, of which a considerable number were found. Collections were
made from 11 different locations, distributed along some four miles of
the course of the stream, from the northern outskirts of Champaign to

its junction with Salt Fork east of Urbana. Five of these locations were
in Champaign and six in Urbana. For convenience they will be designated
by the letters A to K, which will be applied to the locations in the order
of their occurrence along the stream, beginning with the one nearest the
source in the northern Champaign region. The number of collections

in each location varied from one at A to twelve at F, but in most of them
three or more collections were made from each, and the times of making
the collections were distributed over parts of two years, 1922 and 1!)23.

Unfortunately, no similar extensive series of collections had been made



EARTinvoRir Fauna ok Illinois 351

in earlier years; hence, definite comparisons of the fauna with that of

earlier years could not be made, with the exception of locations /•" and G,

where collections had been made at various times in preceding years.

One surprising result of a study of the collections by Mr. Hyatt was
the discovery of the presence of a considerable number of specimens of

Helodriltis vcnctiis hortcnsis, a European species which had been pre-

viously recorded from North America only from California (Michaelsen,

1!100). Thirty-one specimens were collected at one spot in location P on

.\pril lo, ]!)2"^, and a few had been found in neighboring locations in the

preceding month. Still larger numbers were collected at location G in

1923. Since Mr. Hyatt had made collections at these two localities in

1!)21. and the writer also at various times in jireceding years had made
collections in the same ]3laces without finding any representatives of this

species, it seems reasonable to assume that a recent introduction into this

region has occurred.

Another unexpected result was the finding of large numbers of the

species H. chloroticus. A single specimen had been found by Mr. Hyatt

in October, 1921, which was the first record from the Boneyard Branch.

It probably was taken at location F or G, where only eight specimens were
found in the IG collections made in 1922 and 1923. I know of no record

of careful collections prior to 1921 from the banks of the stream at loca-

tion H and below, where Mr. Hyatt found several hundred specimens of

H. chloroticus; hence, the supposition of a relatively recent introduction

of this species has less supporting evidence. The only record of the

species being found in Illinois ])rior to 1921, which is known to the writer,

is that of a dead specimen found Sejjtember 12, 1918, by F. C. Baker
while hunting mollusks in a shallow ])lace in the Salt Folk about nine

miles east of Urbana. The waters of the stream where the specimen was
found were carrying much sewage contamination received from the Bone-

yard Branch at Urbana. An examination by the writer of the shores at

a few points np stream from the place where the specimen was found,

failed to disclose the presence of other specimens.

Another species of which specimens were found to be most abundant

in badly contaminated localities is H. SHbntbiciiiidiis (Eisen). It has been

abundantly represented since 1911 but was not found during the first few
years of the period beginning with 1893.

The accompanying table shows the numbers and distribution of the

siiecimens of the Hyatt collections and requires but little explanation.

Locations A, B, and C were those which were most free from sewage

contamination. The first vertical column of figures gives the total num-
ber of collections made at each of the locations, the next one shows the

total number of specimens from each location, and the following columns

show the total numbers of specimens of each of the species as found at

each of the stations. The lower part of the table contains footings show-
ing the total numbers of specimens of each of the species represented.



352 Illinois NAxriiAL History Sukvky BuLLirriN

In addition to these collections which were all from the banks of one
stream, other collections were made in rivulets or ditches tributary to the

stream, or in adjacent fields. The more pertinent features of a few of

these will be mentioned. In a field near location A a collection of <S0

specimens included TT Hclodrihts rosciis. one Octolasiitin lactcutn and two
Diplocardia communis. A collection of 3G7 specimens from near the

margins of a ditch near location C contained 350 D. singiilaris (Ude),
the others being common upland species. A collection of 209 specimens
from a small tributary stream near location D had 18 Hclodrilus
tetracdriis (Savigny), two of the variety H. t. hercynius (Michaelsen),

three of H. tenuis, and the others were common upland species. A col-

lection of 21 specimens from the margin of Salt Fork above the entrance

of Boneyard Branch, and where there was no sewage contamination, had
11 Spargcinopliilus ciscni Smith (1805), 8 Hclodrilus tctracdrus, and two
H. caligiuosns trapczoidcs. Sparganophilus ciscni is widely distributed

in the North Central States east of the Mississippi River and is abundant
in the mud of the bottom and margins of many of their rivers and lakes,

but does not appear to thrive in waters badly contaminated by sewage.

T.\BLE I

DiSTEIBUTlON OP BONEY.-VRD Bl!.\NCH SPhX'IES OF EARTHWORM.S



EARTinvoRM Paixa of Illinois 353

ADDITIOXS TO THE LIST OF ILLINOIS EARTHWORMS
Hclodrilus bcddardi was not reported in the writer's list of Illinois

species in 1!I15. but in a later pa]ier ( lUlT ) dealing with the distribution

of North American Lu.mbkicidai:. Illinois was included among the "new
localities" in the account of that species. The specimens on which the

record was based had been collected in October. 1910. by Dr. P. S. Welch,
then a graduate student, who found them in a field north of Urbana.
They were not carefully studied until 1915. Several specimens have more
recently been collected near Mimcie. "20 miles east of Urbana. In both of

these localities the specimens were found in damp places near standing

water in pastures. The finding ol H. zriictiis liortcitsis and H. cJiloroticiis

in Illinois was mentioned in a paper by the writer (1!I24) dealing with the

calciferous glands of Lu.mbricid.-\e. Dr. Libbie Hynian of the University

of Chicago collected specimens of H. chloroticiis at Fox River Grove,

Illinois. May S, 192(5.

Hclodrilus octacdnis has recently been found in two difYerent Illinois

localities. In November, 1935, S. L. Neave, a chemist of the State Water
Survey, found several s]iecimens in a very restricted area near the new
sewage-disposal plant iri the outskirts of Urbana: and in November, 192(),

J. F. M filler, a research assistant, found specimens at Starved Rock, Illi-

nois, in moss in crevices of the rock and crawling about on stems of

vegetation. Lumhviais nibcUiis was represented in a collection at LaSalle,

Illinois, in the auttnun of 1935, made by Dr. R. E. Greenfield of the De-
partment of Chemistry at that time, who found them under debris on
the banks of the Illinois River.

One specimen of a new form, together with specimens of other
species, was collected by H. \'. Heimburger. .\pril 16, 1914, from the

banks of a small stream tinwing into the Sangamon River a few miles

below White Heath, Illinois. The writer had sagittal sections made from
one half of the anterior U somites, which showed that the specimen in

some important characters resembles H. pahistris Moore (1895). The
specimen and sections were turned over to ^Ir. Heimburger, then a grad-
uates student at the University of Illinois, and were part of the material

used by him in the preparation of a thesis as a part of the requirements
for a degree ( .\. AI.). After an interval of several years the sections

have been returned to the writer for examination and use in the descrip-

tion of the species, but the unsectioned part has not been available for

study.

Helodrilus heimburgeri n. sp.

Length, T.^ cm. Diameter, 0.35-0.3 cm. Color, very little pigmenta-
tion. Somites. 113. Setae, closely jiaired. Prostoniium, epilobic.

Clitellum, 35-33 and encroaching slightly on 33. First dorsal pore on 5 G.

Male pores, paired on posterior part of 15. between seta lines b and c;

surrounded by prominent glandular elevations. Oviducal pores, on 14

slightly dorsad of b. Septa 11 .13. 13 13. and 13/14 somewhat and
progressively thickened, the latter about two or three times as thick as

septa anterior to 11. The calciferous gland has inconspicuous lateral



354 Illinois Natikal History Sihvky Bullktix

pouches in 10; has no conspicuous enlargements in 11 and 12; longi-

tudinal chambers not much over -40 in number. Hearts, paired in T-11.

Spermaries, paired in 10 and 11. A pair of large chambers or atria in

posterior part of 15, with large gland masses extending into 15 and IG,

the latter one being smaller ; sperm ducts extend dorsad on the anterior

walls of atrial chambers and open into them at their summits. Sperm
sacs, two pairs, in 11 and 12. Ovaries, paired in 13. Spermathecae lack-

ing. Ovisacs, paired in 14 and open into the cavity of somite 13.

One specimen, collected near White Heath, Illinois, by H. V. Heim-
burger.

Halotypc.—Sections of a part of the specimen in the collection of the

writer.

But little attention was given by the writer to the external characters

of the specimen when it was available, but a memorandum was made of

the location of the clitellum. For certain other features the data of Air.

Heimburger have been utilized. The seemingly close relationship to the

species described in 1895 by Dr. H. F. Moore under the genus name
Bimastos, which species until the present time has been unique among the

LuMBRiciDAE in the characters of the distal parts of the sperm ducts,

has added to the interest felt in making a study of the new form. A com-
parative study has been facilitated by the use of three series of sections

of H. palitstris made from specimens kindly sent to the writer by Dr.

Moore several years ago.

External Characters
Rather small in size and also similar to H. paliistris in having a

moderate number of somites, closely paired setae, and conspicuous gland-

ular enlargements on 15, surrounding the external orifices of the spermi-
ducal apparatus. The specimen was seemingly not in a state of sexual

activity at the time of fixation, but apparently had passed through such
a state previously and the gonads were of diminished size. The location

of the clitellum on 25-32 very definitely distinguishes the new species

from H. palustris in which the clitellum is on 23-2!S. The clitellum was
stated by Mr. Heimburger to be nearly complete and to include the ventral

setae. He also stated that no trace of tubercula pubertatis was found.

The two species show marked similarity in the locations of the first

dorsal pores; the external openings of the spermiducal organs on the

posterior part of 15 and a little dorsad of seta line h; the oviducal pores

on 14 slightly dorsad and posteriad of b; and of the nephridiopores, in

the anterior part of the somites with some of them opening a little dorsad
of seta line b, and others approximately midway between seta line d and
the mid-dorsal line. Moore in his description of the nephridia of H
palustris states : "The external opening is near the ventral couple of

setae." An examination of the sections from three of his specimens re-

veals a variability in the positions of the openings similar to that of the

new species. Like variability has been noted by certain other writers and
myself in the location of these pores in other species of Lumbricidae.
(Langdon, 1895, p. 215) (Smith, 1915 and 1925)



Eaktuworm Faiwa of Illinois 355

Internal Characters

The septa connecting the alimentary tract with the body wall are

mostly without much thickening. Septa 11/lv. 12 13. and 13'1-i are

somewhat thickened with the thickness gradually increasing from anterior

to posterior; 13/14 being most thickened, but not very strongly. H.
paliistris differs in having none of the septa with increased thickness.

The deeply staining glandular bodies attached to the wall of the pharynx

and anterior esophagus in somites 4-6 in H. palusiris are represented in

only 4 and 5 in the new species ; the space in G being largely filled by a

mass of cells of different type and but lightly stained. The calciferous

gland is similar to that of H. palustris (Smith, 1924) with approximately

uniform diameter in 10-12, with paired esophageal pouches in 10, and
but few more than 40 longitudinal chambers posterior to 10. Communi-
cations of the chambers of the gland with the pouches in 10 were found
in both species and none were found elsewhere. No especial differences

have been noticed between the two species in the location and relations

of the crop and gizzard, respectively, the former in 15 and Ui and the

latter in IT and IS.

Circulatorv system.—This has not been studied in detail otherwise

than to determine the relations of the hearts and lateral-longitudinal

vessels to the other vessels of the vascular system and to the calciferous

gland. Five pairs of hearts are present in T-11 and have the usual rela-

tions to the dorsal and ventral vessels. The hearts of 11 are similar in

size to the others. An examination of the three series of sections of H.

palustris resulted in finding similar conditions in them except that in two

of them the hearts of 11 were much smaller than the others. In no in-

stance was there any indication of any of the hearts passing into the wall

of the alimentary tract in a part of their course, as described by Moore

(1895, p. 489) in some of the specimens examined by him. The lateral-

longitudinal vessel of one side of the specimen of the new species, which

was included in the sections studied, extends through the space between

the anterior pairs of hearts and the esojihageal wall to the posterior part

of 9, and then dorsad and mesad along the anterior surface of septum
9 10 until near the dorsal side of the esophagus where with a turn poster-

iad it extends through the septum and presumably joins the dorsal vessel

about midway of the length of somite 10. Since the sections do not

include much of the dorsal vessel and the last ones are imperfect, a more
positive statement cannot be made. In his description of H. palustris,

Moore states : "A pair of esophageal vessels arise from the sub-intestinal

trunk in somite X and pass laterally forward to supply the tissues sur-

rounding the anterior portion of the alimentary canal." Elsewhere on

the same page he says. "The vascular system has not been investigated,

except in a very general way." The writer has not found among the

LuMBRiciD.\E studied by him any species in which the lateral-longitudinal

vessels arise from the ventral vessel, and but few in which they do not

have their posterior union with the dorsal vessel in 12. The three series

of sections of H. palustris available for comparison include a transverse.



356 Illinois Natukai, HisTnitv Sirvky Bvij.etin

a sag-ittal, and a frontal series. All of them have been utilized but have
not always been equally helpful for each particular problem. In all three

specimens the course of the lateral-longitudinal vessels has been similar

to that found in the new species. They extend to the posterior part of

9, then dorsad and mesad anterior to septum 9/10, then through the

septum into 10, where they join the dorsal vessel. The junction with the

dorsal vessel is clearly shown in two of the series and nearly as certainly

in the third one.

Reproductive organs.—There is marked similarity between the two
species in respect to the reproductive organs. There is agreement in the

number and location of the gonads in 10, 11, and 1.3, and of the sperm
sacs in 11 and 13. Spermathecae are lacking in both. No essential differ-

ences have been noted in the characteristics of the oviducal organs. The
characteristics of the spermiducal organs are of especial importance in

determining the relationship of this species to others, and it wotild be

highly desirable to have specimens more nearly at the height of sexual

activity than is the only one of the new species now available. In this

specimen the maximum height of the atrial chamber including the thick

glandular wall, as seen in sagittal sections, is but little more than half of

the dorso-ventral diameter of the worm. The apex of the atrial cavity,

which is the place where the slender cylindrical lumen of the sperm duct

opens into that cavity, is about one-third of the diameter of the worm from
the ventral margin, as seen in section. In the specimens of H. palustris

the chamber and cavity are more nearly cylindrical and extend nearly to

the dorsal wall of the body cavity. In the new species, as in the other,

the course of the sperm duct after reaching somite 15 is dorsad along the

anterior wall of the chamber, going deeper and deeper into the glandular

wall tissue, until finally reaching the uppermost part of the chamber, or

atrial cavity, where the lumen of the duct is continuous with the cavity.

No modified setae with related glands in 13 and 16 comparable with those

of H. palustris have been found in the new form, but perhaps such setae

may be present at the time of sexual activity. Large masses of gland

cells associated with the wall of the atrial chamber and extending into

the body cavities of 15 and IG are present in the new species and resemble

those of H. palustris in general appearance, but no careful study of their

histological characters has been made. Nothing is known concerning the

presence or absence of spermatophores in the new species at the time of

sexual activity.

Moore created the genus Biiiiastos for the species palustris, in j^art

because of the striking difference from other Lumbricidae in the char-

acter of the terminal organs of the spermiducal a]3paratus. to which he ap-

pHed the terms prostates and atrial chambers. Later writers have used the

name with corrected spelling (Bimastus) as a name for a sub-genus to in-

clude Moore's species and others that resemble it in having no spermathe-

cae and regardless of the presence or absence of atrial chambers. To the

writer, the existence of this latter character in two species that are also

closely related in other ways seems to be a sufficient basis for the restric-



Eakthworm Faixa of Illinois 357

tion of the use of the name Bimastus to these two species and others that

may later be discovered having similar characteristics including the paired

atrial chambers. There may perhaps be as much justification for recog-

nizing a genus Bimastus as there is for the genus Octolasium. If more
were known about the details of the relations of the lateral-longitudinal

blood vessels in the various species of Lumbricidae, it might aid in the

determination of a more correct classification. The similarity between
H. palustris and the new species in the course of the lateral-longitudinal

vessels seems to be a matter of considerable significance. The onlv other

species in which the writer has found a similar course in these vessels is

H. oclacdrns ( Savigny ) . but in this species there are several important
characters in which it differs materially from the Bimastus group.

The lateral-longitudinal vessels of the three last-named species seem
noticeably smaller and less conspicuous than those of other species in

which these vessels join the dorsal vessel in 12.

DISTIXGUISHIXG CHARACTERS OF ILLINOIS SPECIES
A list of species, together with statements of the important characters

which serve as the basis for determining their systematic relationships,

can be presented in a convenient and compact manner in tabular form
(Table II), as was done in an earlier paper on the species of the State

(Smith, 1915). Before presenting this list, reasons will be given for

changes in the statements of some of the characters of certain sj^ecies

from those given in the former list or from those commonly found in the

literature dealing with such species.

In the former paper the sperm sacs (if H. tctmccirus and of its variety

hcrcyniiis were listed as being contained in somites 0-12, in conformity
with statements conunonly made by writers on the group. Since the

majority of the specimens examined by the writer lack sperm sacs in 10,

though small ones are present in that somite in occasional specimens, they
are listed as in 9. 11. 12. A change has also been made in the location

given for the spermathecal pores of the same forms. Instead of 8 9 and
9 10 as stated by earlier writers and in the former paper, the locatii)n of

these pores in most specimens has been found by the writer to be in 9/10
and 10 11. and this location has also been found bv Cognetti (190.")) to

be the normal one in European specimens (Smith, 1917. p. 1(52).

Specimens apparently related to H. tctracdrus. but having sjiermi-

ducal pores on other somites than 13 or 15, have been found by investi-

gators in Europe, and certain species, varieties, or forma have been named
on the basis of such specimens. Tctragomints f^upa Eisen with spermi-
ducal pores on 12 was described from specimens collected in Xorth
.America near Niagara Palis, and one specimen considered bv Eisen as

the type and presented to the L'nited States National Museum was later

studied by the writer and found to be in all probability an abnormal
representative of H. t. hcrcyiiiiu (Smith 191T, p. 163). ^lany abnormal
specimens belonging to several difTerent species were found by Mr. Hyatt
in his collections from the banks of the Boneyard Branch, and among



35S Ii-MNOis Nati'rat. History Sirvey Bri.ijjTix



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360 Ii.i.ixoiw N-VTriiAL History Sihvky Bulletin

them were 16 specimens belonging to H . fcfracdnis and two to the variety

Iicrcyniiis. In eight of these specimens asymmetry is found, and in ten

specimens the spermiducal pores are paired on somites other than 13 or

15. Sections were made of parts of these ten specimens and studied with

the following results. In one specimen with spermiducal pores on 14,

the clitellum, tubercula pubertatis, oviducal pores, spermathecal pores,

gonads, sperm sacs, hearts, and calciferous gland were all found one
somite anterior to the location normal in the variety hcrcyniiis. In each

of three specimens with spermiducal ]3ores on 12, the various parts named
above are located one somite anterior to the positions normal in H.
tctnicdnts typicus. In four specimens with the spermiducal pores on 11,

the other organs named are two somites anterior to the positions normal
for specimens of that species. In one specimen with spermiducal pores

on 10, the various other organs named, in so far as they are present, are

three somites anterior to the normal positions. Only the three posterior

pairs of hearts were recognized. In this specimen there are four sper-

mathecae in 4-7 on one side and three in 5-T on the other side. The gen-

eral appearance of a few anterior somites suggests strongly their having
been regenerated. One specimen that at first glance with a lens showed
spermiducal pores on 9 was found on more careful study to have lost some
anterior somites (probably four) and had just begun regeneration for

their replacement. Thus far the writer has not made a sufficiently care-

ful study of the specimens with spermiducal pores on 11 or on 13 to pro-

vide a basis for a satisfactory conclusion concerning the probable cause

of such departures from the normal numerical relations—whether it may
be due to injury and subsequent incomplete regeneration or to some other

cause.

H. venetus hortensis is given in the table as having a length of 4-10

cm. instead of the 3.5-5 cm. found in an earlier paper (Smith, 1917) and
based on the statements of European writers. Specimens in the collec-

tions studied by the writer included several that were 7-10 cm. in length.

They had been anesthetized before fixation and were in a well-extended

condition.

Specimens of H . octacdrus from Norway, Colorado, and Illinois have
been sectioned, and in them the writer has found hearts in 7-9 only.

In specimens from Virginia no hearts have been found posterior to 10.

In the other species of Lumbricidae listed the posterior pair of hearts

is in 11.

Specimens of H. tenuis are usually without spermathecae, but the

writer (1917, p. 177) has reported specimens from Michigan and Indiana

with spermathecae imperfectly developed or in reduced numbers (less

than four), and more recently has found three specimens from Homer
Park, Illinois, which also have spermathecae in reduced numbers or im-

perfectly developed.



EAiiTinvon.M Faina ok Illinois 361

GEXERIC XA.MES OF LU.MBRICIDAE

There has been much confusion in the present century in the use of

generic names for Luxibricidae. In 1845, Hoffnieister created a genus
Hdodrihts for a species oculalus which he erroneously beHeved to differ

from related forms in the absence of a clitellum in all stages of the life

history. The related species were left in the genus Lumbricus. In 1ST4,

Eisen separated the species of Lumbricus into four groups, leaving but

few species in Lumbricus and creating three new genera : Allurus,

Dendrobaena, and Allolobophora. Michaelsen, in a monographic paper
(1900a) on Oligochaeta, replaced the name AUurus Eisen, which was
jireoccupied, by the new name Eiseniella Michaelsen. He also substi-

tuted the genus name Helodrilus Hoffnieister for Allolobophora Eisen,

iLsing the latter name for a subgenus of Helodrilus. He felt that a strict

adherence to certain rules of nomenclature, which he was obligated to

follow, required such substitution. In this procedure he was followed by
the majority.of writers of systematic papers dealing with Lumbricidae.
During the past few years there has been a rather general tendency among
various writers, including Michaelsen, to restore the ,genus Allolobophora
and discard Helodrilus. Five groups—Eiseniella, Eisenia, Dedrobaena.
Bimastus, and Eophila—are variously treated as distinct genera, or as

subgenera of Helodrilus or of .-Mlolobo]5hora, depending on which of the

latter happens to be recognized as a valid genus. Such diversities of

terminology cause little inconvenience to the specialist familiar with the
situation, but are naturally confusing to others. In the present paper the
writer has preferred to follow the precedent .set in his earlier paper ( lOlT)
based on Michaelsen's paper of 1010. The real need for a satisfactory

system of nomenclature carefully followed is obvious.

LITERATURE CITED
The following list includes the papers to which direct references are made

in the text. More extensive lists of the literature on Oi.igochakta will be found
in the bibliographic lists in some of the papers here listed, especially in those
of Beddard (1S95), Michaelsen (1900a and 1910). and of Smith (1917 and 1924).

Br.i)i)Ani). P. E.

1S95. A Monograph of the Order of Oligochaeta. Oxford.

COGXEITI DE MaRTILS, L.

1905. Lombrichi liguri del Museo civico di Genova. Ann. Mus. civ. Stor.

nat. Genova. (3) 2:102-127.

EisK.x, G.

1S74. Bidrag till Kannedomen om New Englands och Canadas Lumbri-
cider. Ofv. Vet. Akad. Forh.. 31:41-49.

Gar.max, H.

18SS. On the Anatomy and Histology of a New Earthworm (Diplocardia
communis, gen. et sp. nov.). Bull. III. State Lab. Xat. Hist.. 3:47-77.

Heijiijurgkr. H. V.

1915. Notes on Indiana Earthworms. Proc. Ind. Acad. Sci.. 1914.



362 iLUNOis Natural History Svrvk.y BuLurriN

Laxgdox, Fanny E.

1895. The Sense Organs of Lumbricus agricola Hoffni. Jour, ilorph.,

11:193-234.

Michaelsex, W.
1900. Die Lumbriciden-Fauna Nordamerikas. Ahh. nat. Ver. Hamburg,

16:1-22.

1900a. Ollgochaeta. Das Tierreich, 10 Lief, xxix-575 pp. Berlin.

1910. Zur Kenntnis der Lumbriciden und Hirer Verbreitung. Ann. Mus.
Zool. Acad. Imp. Sci. St. Petersburg, 15:1-74.

Moore, H. F.

1895. On the Structure of Bimastos palustris, a New Oligochaete. Jour.
Morph., 10:473-496.

Sjiitii, F.

1S95. A Preliminary Account of two New Oligochaeta from Illinois. Bull.

III. State Lab. Xat. Hist., 4:138-148.

1900. Notes on Species of North American Oligochaeta.. III. List of

Species found in Illinois, and Descriptions of Illinois Tubificidae.

Bull. III. State Lab. Nat. Hist.. 5:441-458.

1915. Two New Varieties of Earthworms with a Key to described Species
in Illinois. Bull. III. State Lab. Nat. Hist., 10:551-559.

1917. North American earthworms of the family Lumbricidae in the col-

lections of the United States National Museum. Proc. U. S. Nat.
Mus., 52:157-182.

1924. The calciferous glands of Lumbricidae and Diplocardia. III. Biol.

Monographs, 9:1-76.

1925. Certain Differences between Text-book Earthworms and Real Earth-
worms. Trans. III. State Acad. Set., 17:78-83.

Smith, F., and Gittiks, E. M.

1915. Two New Species of Lumbricidae from Illinois. Bull. III. State Lab.
Nat. Hist., 10:545-550.