THE GBAPSOID CBABS OF AMERICA. 129 



KEY TO THE AMERICAN SPECIES OF THE GEXCS FIN MSA. 



A*. Carapace with a ridge entirely across hinder part of carapace, behind which 



the surface slopes steeply down. 



B\ Second joint of palpus of maxilliped short and stout. 

 C 1 . Ridge on carapace sharp. Fingers not gaping. Last segment of male 



abdomen semicircular transvcrsalis, p. 131. 



C*. Ridge on carapace blunt. Fingers gaping. Last segment of made ab- 

 domen subtriangular faxoni, p. 133. 



B 1 . Second joint of palpus of maxilliped long and narrow. 



C 1 . Sharp ridge across front patagonicnsis, p. 135. 



C*. No sharp ridge across front cristata, p. 134. 



A*. Carapace without ridge ou hinder part of carapace or with a ridge on car- 

 diac region only. 

 B 1 . Pol lex of cheliped distinctly developed. 



C 1 . Dactyl us of third leg strongly falcate, the corneous tip bent at an 

 angle to the general outline of the segment. Females much larger 

 and softer than males. 



D 1 . Merus of third leg of male more than twice as long as wide. Fingers 

 of female not gaping. Thumb of male horizontal. Carapace ob- 

 long faba, p. 142. 



D*. Merus of third leg of male twice as long as wide. Fingers of female 

 gaping. Thumb of male deflexed. Carapace pointed at sides. 



littoralis, p. 145. 



O*. Dactylus of third leg straight or slightly curved, the corneous tip con- 

 tinuing the general line of the segment. 



D\ Fourth leg when extended not reaching end of merus of third leg. 

 B 1 . Carapace very wide, nearly 3 times as wide as long. Third leg 

 enormously large in proportion to body. 



F*. Chela stout. Propodus of second leg wide longipes, p. 137. 



F*. Chela feeble. Propodus of second leg narrow. 



tubicola, young, p. 165. 



E 1 . Carapace twice or little more than twice as wide as long. Third 

 leg not enormously large in proportion to body ; merus less than 



twice as long as wide floridana, p. 138. 



D*. Fourth leg when extended reaching end or beyond end of merus of 



third leg. 

 E 1 . Propodus of third leg slender, twice or more than twice as long as 



wide. 

 F 1 . Carapace twice as wide as long; a cardiac crest present. 



say ana, p. 156. 

 F*. Carapace less than twice as wide as long; no cardiac crest. 



minuta, p. 150. 



E 1 . Propodus of third leg not slender, less than twice as long as wide. 

 F 1 . Propodus of third leg as wide as long or nearly so. 



G 1 . A blunt ridge on cardiac region cylindrica, p. 159. 



G*. No ridge on cardiac region. 



H 1 . Carapace of female twice as wide as long. Propodus of last 

 two legs squarish, much wider at distal end than proximal 



end of dactylus tomentosa, p. 141. 



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