190 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 21 



Diagnosis: Sides of carapace subparallel; no constriction at base of 

 hepatic tooth ; hepatic tooth large, rectangular, and broadly but distantly- 

 joined with postorbital. Carapace smooth and bare, branchial tooth 

 scarcely projecting laterally. Rostrum small, horns separated by a sinus 

 equal to one horn inverted. A preorbital tooth. Legs short and stout, 

 propodi unarmed. Male first pleopod with a blunt tip and two opposing 

 channeled projections, one on either side of a median cleft ; a "tongue" 

 in opening. 



Description: Carapace smooth and not distinctly areolated. Rostrum 

 deeply notched, the inner margins of the horns slightly concave, the 

 outer convex. A small, triangular preorbital tooth ; postorbital tooth 

 small. Margin between the postorbital and the large tooth at the 

 anterolateral angle concave and transverse. About midway between the 

 anterolateral tooth and the posterior margin of the carapace, a large 

 tooth pointing forwards and outwards; sides of the carapace in front 

 of the posterior teeth nearly parallel; posterior margin with a strong 

 convexity in the middle. 



Chelipeds stouter, and except in old males, shorter than the first 

 ambulatory legs ; carpus carinate on the outer side ; hand long and 

 narrow, palm oblong, subcarinate above, becoming inflated with age; 

 fingers slender, bent downward and curved inward, the inner margins 

 dentate and contiguous throughout their length ; in old males becoming 

 more or less gaping at the base. 



Ambulatory legs successively decreasing in length posteriorly, 

 penultimate articles subcarinate, dactyls slender, spinulous below, and 

 terminating in sharp, slender claws. 



Abdomen of the female subelliptical, the last somite triangular. 

 (Holmes, modified) Abdomen of the male with sixth segment longer 

 than fifth, both segments wider than long. (Rathbun, 1925) 



Material examined: 484 specimens from 133 stations. (See Table 

 33) From Rosario Beach, Skagit County, Washington, to Asuncion 

 Point, Lower California, Mexico, and including the islands of Santa 

 Cruz, Santa Barbara, San Nicolas, Santa Catalina, and San Clemente, 

 California, and San Benito, Lower California. 



Measurements: The dimensions of the largest male and female in 

 Hancock collections are given in tabular form for purposes of com- 

 parison. The male is not the largest on record, a male measuring 107 

 [not 170] by 93 mm and a female measuring 92 by 78 mm having been 

 recorded by Weymouth (1910, p. 28). Measurements are in millimeters. 



