272 CALIFORNIA ACADEMY OF SCIENCES. 



Ocnerodrilus Eisen. 



Small oligochetes inhabiting soil, water, or both. Cli- 

 tellum comprises the oviduct and the male pore. 



Spermathec£e, with or without diverticula, present or 

 wanting; in somite ix or viii, generally in ix. Sperm- 

 athecal pores in front of inner couple of sette. 



No differentiated penial setae: the inner pair in somite 

 xvii either wanting entirely or wanting in one seta, or 

 present. Nephridia paired, after the first few surrounded 

 by a smaller or greater quantity of peritoneal cells. 



Alimentary canal without gizzard and typhlosole, but 

 with one pair of diverticula in somite ix. These diverti- 

 cula connect with the oesophagus in the posterior part of 

 the somite near the posterior septum. No subnervian 

 vessel. One pair of hearts in somite x and one pair in 

 xi. Sometimes a stout connecting vessel in somite ix. 

 The ventral and dorsal vessels are, except in the som- 

 ites, generally only connected in somites x and xi, 

 and sometimes also in ix. One pair of lateral longi- 

 tudinal vessels from the diverticula of the oesophagus. 

 Testes in x and xi. One or two pairs of prostate glands 

 (atria) in somites xvii and xviii opening in the same 

 papilla as the sperm ducts. The epithelial lining of the 

 prostate only one cell thick. 



Synoptic Arrangement of the Species. 



I. Speruiatheca present in somite ix. Lower part of sperm duct not 

 enlarged. 

 1. In the inner couple of set* in somite xvii one seta is wanting. 

 The lower part of the prostate not greatly differentiated. 



a. The spermatheca large, club-like, with several distinct but rudi- 



mentary diverticula. The anterior septal gland is much 

 larger than the one behind in somite vi. The prostate not 

 exceedingly small. O. Beddardi. 



b. The spermatheca is small, slightly indented, but otherwise with 



no distict diverticula. The anterior septal gland twice as 

 long as the gland in somite vi. Prostate gland is unusually 



small. ^- GUATEMALA. 



