70 



BULLETIN 129, UNITED STATES NATIONAL MUSEUM 



distal end; hand slender, slightly compressed, increasing very little 

 in width toward distal end; fingers from a third to a fourth as long 

 as palm, arched, gaping narrowly in basal half. Legs much shorter 

 than chelipeds, decreasing regularly in length from first to fourth; 



fourth leg a little more than half length 

 of first; dactyls minutely spinulous. 



Female: Smaller than male and of 

 very different shape, the carapace being 

 broader anteriorly and narrower poste- 

 riorly; it lacks the long neck of the 

 male, the postorbital spine is longer 

 and not far behind the eye, the hepatic 

 region is more prominent laterally and 

 the branchial region less so. Rostrum 

 shorter than in male, about one-fourth as 

 long as postrostral portion of carapace. 

 Abdomen densely granulate except in 

 the depressions either side of the median 

 elevation. Chelipeds one and a third 

 times as long as carapace and shorter 

 than the first pair of ambulatory legs; 

 fingers nearly as long as palm. 



Measurements. — Male (53957), length 

 of carapace 11.5, width 7.8, length of 

 cheliped 41 mm. Female (17340), length of carapace 7.5, width 5, 

 length of cheliped 10 mm. 



Range. — From Santa Rosa Island, California, to Abreojos Point, 

 Lower California, Mexico. Depth, 21 to 58 fathoms. 

 Material examined. — See table, page 69. 



Genus OREGONIA Dana 



Oregonia Dana, Amer. Journ. Sci., ser. 2, vol. 11, 1851, pp. 270 and 431; 

 type, 0. gracilis Dana; U. S. Expl. Exped., vol. 13, Crust., pt. 1, 1852, 

 p. 105; pt. 2, 1853, p. 1421. 



Carapace subtriangular or suboblong, moderately convex and 

 tuberculate; a large postorbital, but no preorbital spine; rostral 

 spines slender. Antennae visible in dorsal view at sides of rostrum, 

 basal article narrow. Merus of maxillipeds distally truncate, bear- 

 ing the palpus at its antero-internal angle. Chelipeds in male 

 much elongated, somewhat enlarged; palm long, compressed and 

 distally widened. Ambulatory legs of moderate length, slender, 

 and decreasing regularly in length. Abdomen composed of seven 

 distinct segments. 



Bering Sea and North Pacific Ocean. Shallow water to 764 

 fathoms. 



Fig. 18.— Erileptus spinosus, male 

 (53957), maxilliped, x 21.3 



