PART 1 GARTH : PACIFIC OXYRHYNCHA 251 



16a. Male chelipeds with 



palm broad, crested ; 



orbital sinus V-shaped 



Chorilia 



16b. Male chelipeds slender, 



elongate; orbital sinus 



U-shaped . Rochinia 



lib. Rostrum bifid for not more than half its 



length, or at tip only 



17a. Supraocular eave produced anteriorly 

 as a spine . . . Libidoclaea 

 17b. Supraocular eave not produced anteri- 

 orly as a spine 



18a. Basal antennal article narrow; 

 second free segment not overreach- 

 ing rostrum . . . .Pelia 

 18b. Basal antennal article broad, a 

 compound spine at anteroexternal 

 angle; second free segment over- 

 reaching rostrum . Pisoides 

 10b. Rostrum a simple, triangular spine 



Neodoclea 



9b. Supraocular eave and postocular process closely ap- 

 proximated 

 19a. Carapace subglobose, spinate; rostrum involute 



Libinia 



19b. Carapace subtrianglar, nodose; rostrum evolute; 

 orbit outward-looking; basal antennal article 



tapering, not spined Lissa 



8b. Six male, five female free abdominal segments 



Leurocyclus 



Genus SGYRA Dana 



Scyra Dana, 1851a, p. 269; 1852, p. 94. Holmes, 1900, p. 41. Rathbun, 

 1925, p. 195. 



Type: Scyra acutifrons Dana, by monotypy. 



Description: Carapace subpyriform, tuberculated, but not spinose. 

 Rostrum composed of two flattened horns. Orbits small, with a fissure 

 above and below, the lower and sometimes the upper one being open. 



