THE GRAPSOID CRABS OP AMERICA. 63 



which is the chief distinguishing character of Ostracotheres, even 

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

 Cryptophrys in now known to have a three- jointed palp, while Zaops 

 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 PINNOTHERES. 



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

 B 1 . Dactylus of third leg not longer than that of other legs. 

 C 1 . Carapace wider than long. 



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

 E 1 . Dactyli of legs unequal, either the second or the fourth longer than 



the others. 



F 1 . Dactylus of second leg longest. 

 G 1 . Manns widest a little behind distal end. Carapace soft and 



yielding. 

 H 1 . Dactylus of second leg nearly (about seven-eighths) as long 



as propodus ostrcuin, p. GG. 



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



propodus. Legs slenderer than in ostreum holmcsi, p. G8. 



G*. Manus widest at distal end. 

 H 1 . Carapace about one-fifth wider than long. Palm less than 



twice as long as wide gcddesi, p. 70. 



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



twice as long as wide anyclicus, p. 72. 



P*. Dactylus of fourth leg longest. 



G 1 . Carapace suborbicular, front a little produced. Fourth leg 

 longest, not notably slenderer than the others. 



putjcttcnsis, 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 1 . Carapace thin, soft. Dactyli of legs falcate. 



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

 H 1 . Fourth leg strikingly narrower, feebler than the others, Its 

 propodus with subparallel margins. Legs thinly bearded 



on margins ftcrrci, p. 84. 



H'. Fotirth leg narrower than the others, but not strikingly so. 



its propodus strongly narrowed distally. 

 J 1 . A large pit either side of middle. Posterior margin 



straight Itarbatus, p. 88. 



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

 gin convex pubc-tccns, p. 87. 



G 1 . Carapace half again as wide as long. Fourth leg much nar- 

 rower than others stromli, p. 90. 



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



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

 longer than left margarita, p. 91. 



