Article YIII. — Notes on Species of North American Oli- 

 gochmta. By Frank Smith. 



A number of species of Oligochseta have been collected 

 during the present year (i895) at Havana, 111., in con- 

 nection with the work of the University of Illinois Bio- 

 logical Experiment Station. It seems best to give a 

 preliminary account of some of them at this time, al- 

 though a more complete description, with plates, is in 

 preparation. In this account is included some recently 

 obtained information upon Enchytrceus {Halodrilvjs) llt- 

 toralis Verrill. 



Diplocardia ( Geodrllus) singularis Ude. 



In the months of April and May there were found at 

 Havana, 111., many sexually mature earthworms which 

 are probably identical with Geodrihis singularis^ described 

 by Ude (14, p. 69)* from specimens collected at Danville, 

 111. Michaelsen (8, p. 190) has recently shown that a 

 close scrutiny of Ude's description makes it likely that 

 the pores of the prostate glands are upon somites XVIII 

 and XX instead of upon XVII and XIX, and that the 

 male pore is upon XIX, and a, letter recently received 

 from Ude confirms the correctness of Michaelsen's as- 

 sumption. The Havana specimens correspond to the 

 description of G. singularis as thus amended, except iu' 

 minor characters to be mentioned later. 



The poor state of preservation of Ude's specimens 

 made a satisfactory account of the reproductive organs 

 impossible. In having three pairs of spermathecae in 

 YII, VIII, and IX, I^iplocardia singularis agrees with D. 

 communis Garman, and differs from the three remaining 



*Hore mid throughout this paper the full-face parenthetical figures refer to the 

 bibliographical list which follows it. 



