THE GKAPSOID CBABS OF AMERICA. • 129 



KEV TO THE AMERICAN SPECIES OF THE GENCS PINNIXA. 



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

 llie surface slopes steeply down. 

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



C'. 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'. Second joint of palpus of maxilliped long and narrow. 



C\ Sharp ridge across front patagoniensis, p. 135. 



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



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

 diac region only. 

 B\ Pollex of cheliped distinctly developed. 



C*. Dactylus 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\ 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 /^«^«' 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. 

 C*. 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. 

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

 wide. 

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



sayana, p. 156. 

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



minuta, p. 150. 

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

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



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



G*. No ridge on cardiac region. 

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

 two legs squarish, much wider at distal end ti.i.in pi-oximal 



end of dactylus tomcntosa, p. 141. 



63863—17 9 



