440 JUinois iState Laboratory of JSaturaL History. 



the subterminal claw; ramus straight, stout, and 

 from ten to twelve times as long as wide. 



C. FASCiATA O. F. Miiller. 



6 (1). Both spines on the first maxillary process of the 



first pair of maxillae toothed. 



7 (14). Third and fourth segments of the first pair of 



feet not grown together. 



8 (13). Shell not reticulated as in Fig. 3, PI. XLIII. 



9 (12). Dorsal seta of caudal ramus not reaching 



beyond tip of ramus, one and a half times width of 

 ramus from subterminal claw ; ramus more than 

 twenty times as long as wide; terminal claw half 

 the length of the ramus; subterminal claw two thirds 

 the length of the terminal one. C. fuscata (Jurine). 



10 (11). Shell less than twice as long as high (as 5 to 

 3). Terminal claw half as long as the ramus; sub- 

 terminal claw three fourths as long as the terminal 



one. C. TESTUDINARIA U. Sp. 



11 (10). Shell more than twice as long as high (as 13 

 to 6). Terminal claw a third as long as the ramus; 

 subterminal claw two thirds the length of the termi- 

 nal one. C. FiscHERi Lilljeborg. 



12 (9). Dorsal seta of caudal ramus reaching beyond 

 tip of ramus, and width of ramus from subterminal 

 claw ; ramus less than twenty times as long as wide. 



13 (8). Shell of most individuals reticulated as in Fig. 

 3, PI. XLIII. (Keticulation occasionally almost 

 obsolete in old adults.) Terminal claw nearly three 

 fifths as long as ramus, straight; terminal seta not 

 more than a fourth as long as the terminal claw; 

 dorsal seta as long as the terminal one, reaching 

 beyond tip of ramus, and width of ramus from sub- 

 terminal claw ; ramus twelve to fifteen times as long 

 as wide. C. eeticul.\ta Zaddach. 



14 (7). Third and fourth segments of the first pair of 

 feet grown together. C. pubera O. F. Miiller. 



