THE GRAPSOID CRABS OP AMERICA. 63 



which is the chief distinguishing character of Ostracotheres^ even 

 though it be an insuflicient one. At least one of the species of 

 Cryptoyhrxjs in now known to have a three-jointed palp, while Zaojis 

 depressa^ of which only the male is recorded, is perhaps no more 

 atypical than some other males of Pinnotheres. 



KEY TO FEMALES OF AMERICAN SPECIES OF THE GENUS PINNOTHEIIES. 



A*. Palpus of outer maxilliped small, not nearly half as large as meruss. 

 B*. Dactylus of third leg not longer than that of other legs. 

 C\ Carapace wider than long. 



D\ Legs of each pair (right and left) similar. 

 E\ Dactyli of legs unequal, either the second or the fourth longer than 

 the others. 

 F\ Dactylus of second leg longest. 

 G\ Manus widest a little behind distal end. Carapace soft and 

 yielding. 

 H\ Dactylus of second leg nearly (about seven-eighths) as long^ 



as propodus ostrciini, p. OG. 



H^ Dactylus of second leg shorter, about two-thirds as long as 

 propodus. Legs slenderer than in ostreum — holmcsi, p. GS. 

 G'. Manus widest at distal end. 



H\ Carapace about one-fifth wider than long. Palm less than 



twice as long as wide geddesi, p. 70. 



H^ Carapace wider, one-third wider than long. Palm more than 



twice as long as wide angclicns, p. 72. 



F*. Dactylus of fourth leg longest. 

 G\ Carapace suborbicular, front a little produced. Fourth leg 

 longest, not notably slenderer than the others. 



ptifjcitensis, p. 82. 

 G*. Carapace transversely oblong, or subpentagonal. Fourth leg 

 not longest, but notably slenderer than the others. 



politus, p. 71. 

 E'. Dactyli of legs subequal. 

 F\ Carapace thin, soft. Dactyli of legs falcate. 



G\ Carapace considerably less than half again as wide as long. 

 H*. Fourth leg strikingly narrower, feebler than the others, its 

 propodus with subparallel margins. Legs thinly bearded 



on margins scrrci, p. 84. 



H*. Fourth leg narrower than the others, but not strikingly so. 

 its propodus strongly narrowed distally. 

 .7\ A large pit either side of middle. Posterior margin 



straight harhatus, p. 88. 



J*. A longitudinal sulcus either side of middle. Posterior mar- 

 gin convex puhc>iccns, p. 87. 



G*. Carapace half again as wide as long. Fourth leg much nar- 

 rower than others stromhi, p. 90. 



F*. Carapace completely calcified, hard silvcstrii, p. 91. 



D'. Legs of second pair dissimilar; right propodus and dactylus much 

 longer than left rnarfuvita, p. 91. 



