THE GEAPSOID CRABS OF AMERICA. 185 



KEY TO THE AMERICAN SPECIES OF THE GENUS CYMOPOLIA. 



A 1 . Length of second ambulatory leg not more than twice width of carapace. 

 B 1 . Last sternal segment does not form a laminiform crest which is con- 

 spicuous in dorsal view. 



C 1 . The merus of second and third ambulatory legs has at its supero- 

 distal angle an obtuse lobe, more or less prominent, sometimes 

 atrophied. 



D 1 . Carapace with four lateral teeth on each side (not counting extra- 

 orbital tooth), diminishing in size from front to back. Ambulatory 



legs with 3 or 4 large teeth on anterior margin cristatipes, p. 186. 



D 2 . Carapace with two lateral teeth on each side, sometimes with rudi- 

 ments of a third farther back. Ambulatory legs without large 

 teeth on anterior margin except the distal tooth. 

 E 1 . Pterygostomian lobe reaching well beyond inner suborbital 



lobe rathbuni, p. 198. 



E 2 . Pterygostomian lobe not reaching beyond suborbital lobe. 

 F 1 . Antero-lateral teeth near together, wider than intermediate 

 sinus. 



G 1 . Antero-lateral teeth blunt alternata, p. 188. 



G*. Antero-lateral teeth acute. 



H 1 . Outer margins of exorbital teeth converging anteriorly. 

 Posterior margins of propodus and dactylus of first am- 

 bulatory bare in mature male zonata, p. 190. 



H*. Outer margins of exorbital teeth subparallel. Posterior mar- 

 gin of propodus and dactylus of first ambulatory clothed 



with shaggy hair in mature male affinis, p. 196. 



F". Antero-lateral teeth distant, narrower than intermediate 



sinus bahamensis, p. 200. 



C*. The merus of second or second and third ambulatory legs has at its 



supero-distal angle a prominent lobe which ends in a sharp point. 

 D*. Outer suborbital lobe strongly convex on anterior margin. Antero- 

 lateral teeth blunt. 

 E 1 . Last leg reaches end of merus of third leg. Two lateral teeth on 



carapace obesa, p. 205. 



E*. Last leg falls short of end of merus of third leg. Three lateral 



teeth on carapace tuberculata, p. 207. 



D". Outer suborbital lobe truncate and nearly straight on anterior 



margin. Antero-lateral teeth acute. 

 E 1 . Front quadridentate, teeth well separated. Antero-lateral teeth 



adjacent, sinus narrower than either tooth. 



F 1 . Outer orbital tooth pointing straight ahead. Tubercles of 

 carapace very distinct from the prominences which bear 



them dentata, p. 202. 



F J . Outer orbital tooth with tips turned inward. 



G 1 . Lobe at supero-distal angle of merus of third leg 



acute faxoni, p. 194. 



G s . Lobe at supero-distal angle of merus of third leg obtuse. 

 Posterior margin of propodus of first leg clothed with 



shaggy hair in mature male lucasii, p. 193. 



E*. Front bidentate, each tooth obscurely emarginate. Antero-lateral 

 teeth distant, sinus as wide as tooth isthmia, p. 201. 



