ArticLE [V.—A Representative of the Genus Trichodrilus from 
Illinois.* By JAMeEs E. Krnprep. 
INTRODUCTION 
The description. given in this paper is based upon the detailed exami- 
nation of a single specimen which was pumped from a well in Concord, 
Illinois, June 18, 1915. It was submitted to Professor Frank Smith, of 
the University of Illinois, with a question as to its harmfulness, and after 
this had been answered, was set aside. The specimen is now in the col- 
lection of Professor Smith, to whom I am under obligations for the 
opportunity to study it and for suggestions in the preparation of this 
report. It came into my hands mounted in cedar oil, in good condition 
for external examination, but the sections which were made for examina- 
tion of the internal characters were unfortunately wrinkled in some of the 
most important parts of the reproductive somites, so that conclusive 
evidence for the presence or absence of certain of the reproductive parts 
can not be given, and therefore its exact status can not be established. 
The resemblance of this form to the members of the European genus 
Trichodrilus Claparéde is evident, and many points in its anatomy link 
it with the type species of the genus, T. allobrogum Claparede. No repre- 
sentative of this genus of the Lumbriculidae has as yet been recorded in 
North America, and still other representatives may exist in the kind of 
environment in which the present worm was found. Any small aquatic 
worms which are pumped from our wells from time to time may be 
important in extending our knowledge of Trichodrilus and other genera 
of the oligochaete fauna of the United States. It is desirable that persons 
finding such forms should send them to qualified specialists for identifi- 
cation if they can not themselves determine them with the aid of the 
brief description of the species of Trichodrilus given at the conclusion of 
this paper, thus aiding in the settlement of the position of doubtful forms 
and making known the presence of others, if there are such. 
Besides T.allobrogum, two other species of Trichodrilus have 
been described from Europe, T. pragensis Vejdovsky and T. sanguineus 
(Bretscher). The latter was first described as the type of a new genus, 
Bichaeta (Bretscher, 00), but Piguet (’13) placed it in the genus Tri- 
chodrilus. In the following section the details of structure of the Ih- 
nois form are given as far as the material will permit. Since it seems to 
a * Contributions from the Zoological Laboratory of the University of Illinois, 
No. 119. 
