THE SPIDER CRABS OF AMERICA H 



of the antenna well developed, generally fused with epistome and often 

 with front. Orbits generally more or less incomplete. Hooked 

 hairs almost always present. Male openings coxal. The palp of the 

 external maxillipeds is articulated either at the summit or at the 

 antero-internal angle of the morus. 



Subfamily Inachinae 



Inachinae Alcock, Journ. Asiat. Soc. Bengal, vol. 64, 1895, pp. 160, 162, 



and 168. 

 Inachidae Stebbing, Ann. Durban Mus., vol. 1, pt. 5, 1917, p. 435. 



Ej^es without orbits; the e3"estalks, which are generally long, are 

 either non-retractile, or are retractile against the sides of the carapace, 

 or against an acute postocular spine that affords no concealment. 

 The basal article of the antennae is extremely slender throughout its 

 extent and is usually long. (Alcock.) 



KEY TO THE AMERICAN GENERA OF THE SUBFAliaY INACHINAE 



A^ External maxillipeds somewhat pediform, with the palp large and coarse, 

 merus often narrower than ischium. Basal article of antennae usually 

 subcylindrical or convex on the ventral surface. Carapace usually 

 elongate, narrowed in front. 

 B'. Basal antennal article not longitudinally sulcate. Rostrum long, ap- 

 proaching or exceeding in length the postrostral portion of the carapace. 

 C. Rostrum a slender spine. Merus of outer maxillipeds with an antero- 

 internal notch. 

 D^ Rostrum armed with numerous spines on the lateral margins. Ambu- 

 latory legs armed with numerous spines. Carapace smooth. 



Stenorynchus, p. 13. 



D^. Rostrum armed with a few spines irregularly placed. Ambulatory 



legs with few spines, including a very long spine at end of merus. 



Carapace lumpy Metoporhaphis, p. 19. 



C^. Rostrum more or less deeply divided into two long slender horns. Merus 

 of outer maxillipeds lacking an antero-internal notch. Ambulatory 



legs of last two pairs prehensile Anomalothir, p. 23. 



B^. Basal antennal article longitudinally sulcate. Rostrum short. 



C Merus of outer maxillipeds narrow, suboval, the palp articulating at 

 the summit. Carapace ovate, not much longer than broad, spinous. 



Rostrum bispinous or bidentate Achaeopsis, p. 27. 



C^. Merus of outer maxillipeds subtriangular, notched anteriorly. Carapace 

 elongate, subtriangular, not spinous. Rostrum variable, usually a 

 simple lobe or spine. Ambulatory legs more or less prehensile. 



Podochela, p. 31. 



A 2. External maxillipeds with the merus as broad as the ischium and the palp 



of moderate size. Basal article of antennae flattened or concave ventrally. 



Carapace usually subtriangular. A postocular spine present. 



B*. Eyestalks long and slender, when extended reaching forward beyond 



rostrum. Rostrum bilobed. Basal antennal article little longer than 



broad Eucinetops, p. 84. 



B^. Eyestalks stout or if slender, not reaching forward beyond rostrum. Basal 

 antennal article narrower, considerably longer than broad. 



