190 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3D Ser. 



Meganephridia, most anterior one in III. Testes in X and XI. Sperm-fun- 

 nels in X and XI. Sperm-ducts run on top of muscular layer, between it and 

 the coelomic epithelium. They join only at the pore. Sperm-sacs in IX 

 preseptal, in XII postseptal. Prostates long, slender, tubular, abruptly bent 

 at the pore, sometimes extending over more than one somite. Spermathecae, 

 three pairs in VII-IX, club-like, with an ear-shaped diverticle below the 

 center. 



Septal formula (approximately correct) : — 



VI/VII, VII/VIII, VIII/IX, IX/X, X/XI. 



Habitat. — Champaign, Illinois. Collected by Professor 

 Garman. Through the kindness of Professor Frank Smith, 

 I have in my possession four specimens collected by Pro- 

 fessor Garman, and three specimens collected by Professor 

 Smith himself. The former differ from the latter in the 

 character of the genital zone. It is well worth the while to 

 examine a large number of specimens in order to ascertain 

 if there are not two distinct species now joined under the 

 name of D. communis. 



Genital Zone. — Specimens collected by Professor Gar- 

 man: No. I. No signs of a depressed genital area. There 

 is one pair of comparatively large papillae in the posterior 

 part of XVII, just clearing the groove of XVII/XVIII, with 

 their bases slightly encroaching on XVIII. Besides this 

 pair there are three pairs of smaller papillae in the posterior 

 parts of XX, XXI and XXII, similarly very slightly pro- 

 jecting across the intersegmental grooves posteriorly. No. 2. 

 One pair of papilla in XVII, and one pair in XX, situ- 

 ated as in No. i. No. 3, similar to No. 2. In all these 

 specimens the papillae of the anterior pair are the largest. 



In each one of the specimens collected by Professor 

 Smith there is a depressed genital zone not existing in 

 Garman's specimens. This zone is oblong and almost 

 rectangular. It is surrounded by an elevated ridge similar 

 in shape to that found in D. Udei, but it is not so high. 

 This ridge extends from Y^ XVII-i^ XXI, while the 

 depressed zone extends from XVIII-^ XXI. Inside the 

 ridge there is in specimen No. i a pair of papillae in the 

 posterior part of each of somites XVII and XX and one pair 



