COPEPODA 781 



109 (120) Anal plate without spines, or spines are simple, i.e., do not have 

 two points no 



no (113) Sides of last abdominal segment have spine-like prolongation 

 caudad in 



111 (112) Spines of anal plate few in number, not exceeding five or six. 



Canlhocamptus staphylinoides Pearse 1905. 



\%^^-- Fig. 1231. Anal plate and furca of Canlhacaviplus staphylinoides, X 153. 



A T| — (After Pearse.) 



112 (in) Spines of anal plate numerous. 



Canlhocamptus staphylinus (Jurine) 1820. 



Fig. 1232. Last segment and furcae of male Canlhocamptus staphylinus. 

 (After Schmeil.) 



113 (no) Sides of last abdominal segment do not have spine-like prolongation 



caudad 114 



114 (115) Furca long and slender, nearly four times as long as wide. 



Canthocamptus idahoensis Marsh 1903. 



Fig. 1233. ^ntcSL&oii^maXQ Canlhocamptus idahoensis, X 120. (Original.) 



115(114) Furca short, its length not exceeding twice its width. . . . 116 



116(119) Furca with two setae 117 



117 (118) Anal plate with spines. . Canlhocamptus illinoisensis Forbes 1876. 



118(117) Anal plate without spines. . Canthocamptus hiemalis 'Pe&ise igo$. 



Fig, 1234. Anal plate of female Canlhocamptus hiemalis. X 144. 

 (After Pearse.) 



