210 BULLETIN 1^, UNITED STATES NATIONAL MUSEUM 



lateral epibranchial spines prominent. Rostrum consisting of two 

 spines usually long and slender. Eyes small, retractile against a 

 postocular process; the supraocular eave usually terminates in a tooth 

 or spine. Basal antennal article narrow and either unarmed, or 

 with one or more spines. Merus of outer maxillipeds as broad as 

 ischium, truncated distally, slightly produced at the antero-external 

 angle, and bearing the palp at the antero-internal angle. 



Chelipeds usually slender, often greatly elongated in the male, with 

 the palms broadened and compressed. Ambulatory legs slender and 

 elongate; first pair markedly the longest. Abdomen in both sexes 

 composed of seven distinct segments. 



East coast of America from 40° N. latitude to Barbados and from 

 Cape Frio, Brazil, to Cape Horn; northeast Atlantic to South Africa; 

 Mediterranean; Indian Ocean and Australia to Japan; Galapagos 

 Islands. Depth, 30 to 738 fathoms. 



KEY TO THE AMERICAN 3PECIE3 OF THE GENUS ROCHINIA 



A*. Median spines 6; gastric spines 6; 2 spines on basal antennal article. 



crassa, p. 210. 

 A^. Median spines or tubercles fewer than 6; gastric spines or tubercles fewer 

 than 6. 

 B*. Median tubercles 3; gastric tubercles 3. 



C^ Rostrum longer than remainder of carapace cornuta, p. 217. 



C^. Rostrum shorter, less than half as long as remainder of carapace. 



gracilipeg, p. 218. 

 B^. Median spines or tubercles 4; gastric spines or tubercles 4. 



C. Spines of carapace and rostrum long and slender; a spine at angle of 



buccal cavity hystrix, p. 214. 



C^. Spines or tubercles of carapace short or of moderate length; no spine at 

 angle of buccal cavity. 



D'. Dorsal tubercles mostly large and flat-topped umbonata, p. 222. 



D2. Dorsal tubercles or spines acute, not large and flat-topped. 



E'. Two spines on basal antennal article; an oblique row of 3 spines 

 from the anterior, median, gastric spine to the marginal, branchial 



spine at the widest part of the carapace vesicularis, p. 221. 



E^. Only one spine or tooth on basal antennal article; an oblique row 



of more than 3 spines from the anterior, median, gastric spine 



to the marginal, branchial spine. 



F'. An oblique row of 4 spines from the anterior, median, gastric 



spine to the marginal, branchial spine; 3 branchial spines 



(paired)-- tanneri, p. 216. 



F". An oblique row of 5 spines from the anterior, median, gastric 

 spine to the marginal, branchial spine; 5 branchial spines 

 (paired) occidentalis, p. 220 . 



ROCHINIA CRASSA (A. Milne Edwards) 



Plates 68, 69 and 226 



Amathia crassa A. Milne Edwards, Crust. Reg. Mex., 1879, p. 203, pi. 28, 

 figs. 2-26 (type-locality, between Cuba and Florida, lat. 24° 15' N.; long. 

 82° 13' W., 229 fathoms; holotype, Cat. No. 2862, Mus. Comp. Zool.); 

 Bull. Mus. Comp. Zool., vol. 8, 1880, p. 3. 



