3l6 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 30 Ser. 



Thoracic segments with a median carina on the posterior portion of the 

 upper surface, the carina of the last segment interrupted in the middle and 

 produced into a tooth at the posterior end; postero-lateral angles of the last 

 4 thoracic segments produced backwards and rounded. First 4 segments of 

 the abdomen carinated above, the carinae on the first 2 segments interrupted 

 in the middle and produced posteriorly into a tooth; carina of the third seg- 

 ment continuous and terminating posteriorly in a narrow tooth which points 

 obliquely upwards; anterior portion of the fourth segment smooth above 

 and having a depression behind which is a tooth which is followed by a 

 carina which extends to the posterior end of the segment'where it may be 

 produced into a small tooth ; fifth and sixth segments very short above and 

 smooth, postero-lateral angles of the first 3 abdominal segments very broadly 

 rounded. 



Head carinated above, the carina continued upon the long rostrum which 

 is acute and strongly curved downwards; antero-lateral angle of the head 

 acute, the margin above the angle concave. Eyes large, oval, situated in 

 the base of the rostrum and almost contiguous above. Upper antennae 

 about f the length of the lower and nearly \ the length of the body; first 

 joint of the peduncle elongated, reaching nearly to the tip of the rostrum; 

 second joint a little over half the length of the first and much more slender; 

 third joint \ the length of the second; flagellum a little shorter than the 

 peduncle. Fourth basal joint of the lower antennae extending beyond the 

 first joint of the upper for about \ its length; fifth joint more slender and 

 somewhat longer than the fourth; flagellum about as long as the peduncle. 



First maxillae with the inner plate about f the length of the outer and 

 furnished with 2 plumose setae; outer plate armed distally with 7 spine-teeth 

 each of which is furnished with i or 2 small curved teeth near the middle; 

 first joint of the palp about as wide as long, second joint elongated, armed 

 distally with several slender spines and reaching considerably beyond the 

 end of the outer plate but not to the tip of the spine-teeth. Inner plate of 

 the second maxillae shorter than the outer but of about the same width. 

 Inner plates of the maxillipeds very small, oblong, the distal margin fur- 

 nished with spines and setae and reaching scarcely beyond the base of the 

 outer plates; outer plates not reaching the middle of the large second joint 

 of the palp; third joint of the palp pyriform; fourth joint a large, curved, 

 acute claw nearly as long as the preceding joint. 



First gnathopods with the third joint truncated below and somewhat 

 produced at the postero-inferior angle ; carpus produced posteriorly into an 

 oblong, distally rounded process which is curved downwards; hand ovate, 

 anterior and posterior margins evenly curved and equally convex; palm 

 occupying about f the posterior margin and terminated by a short spine; 

 dactyl rather slender, evenly tapering to a sharp point. The second gnatho- 

 pods very closely resemble the first but are somewhat larger, with the pro- 

 podus and the posterior lobe of the carpus slightly more narrow. First 2 

 pairs of pereiopods rather short, the dactyls \ the length of the propodi; 

 the 2 following pairs longer with the dactyls slightly longer than the propodi; 

 posterior pair of pereiopods large, elongated, nearly twice the length of the 

 preceding pair and reaching beyond the tip of the uropods. 



