153 



i6 (17) Brain circular santa'rosce* 



17 (16) Brain distinctly longer than broad. 



18 (21) Spermathecal diverticula subcylindrical, no glands at ectal 



opening of duct. 



19 (20) Length 20-25 mm. ; somites, 65 ; anteseptal part of ncphridia 



ovate, postseptal part slender, with a dorsal lobe about same 



size as anteseptal part agricola't 



20(19) Length 10-12 mm.; somites about 55; nephridia large, ante- 

 septal part large and swollen and filled with opaque gran- 

 ules saiitcvbarbarce 



21 (18) Spermathecal diverticula finger-like and pendent ; two glands 



at the ectal opening of spermathecal duct popofiana 



22 (15) Spermathecse with more than two diverticula. 



23 (26) Peptonephridia simple and unbranched. 



24(25) Brain two thirds as broad as long, posterior margin convex; 

 unicellular glands at ectal opening of spermathecal duct ; 

 length 25-30 mm. ; somites, 60-69 longa 



25 (24) Brain one and two thirds times longer than broad, angular, 



posterior margin truncate ; no glands at ectal opening of the 

 spermathecal duct; length, 11-20; somites, 43—55 douglasensis 



26 (23) Peptonephridia with distinct branches. 



27(28) Two set^e per bundle, rarely three or four; nephridial duct 

 arises from caudal end of postseptal part agilis 



28 (27) Setae predominantly four or more per bundle; nephridial duct 



arises from the anterior end of the postseptal part. 



29 (32) Anterior margin of the brain concave. 



30 (31) Length, 24—33 nim. ; somites, 62-67; spermathecse with 3-4 di- 



verticula ; no glands at the ectal opening of the spermathecal 

 duct finna 



31 (30) Length, 9— 17 mm.; somites, 52— 59;spermathecae with 7 divertic- 



ula ; glands present at the ectal opening of the spermathecal 

 duct tenera 



32 (29) Anterior margin of the brain convex. 



33 (34) Branches of the peptonephridia arise from a common base; 



length, 8 mm macgregori 



34 (33) Branches of the peptonephridia arise dendritically and not from 



a common base; length over 8 mm. 



35 (36) Dorsal vessel arises in XX oconeensis 



36 (35) Dorsal vessel arises in XVI calif ornica 



*SperniathecEe as a rule with onh^ two large diverticula, as the ke^' indi- 

 cates; but in one specimen Eisen found that the large diverticulum was re- 

 placed on one side by three smaller ones. 



tA variety of this species has the terminal portion of the spermatheca 

 glandularly thickened for a short distance from the mouth and one or two 

 solid outgrowths alternating from the accessory sacs. 



