34 CALIFORNIA ACADEMY OF SCIENCES. 



spines on the cardiac region and a small spine or tubercle near the pos- 

 terior end of the intestinal. The spines on the branchial regions are 

 numerous and variable, but there is usually a more prominent spine near 

 the middle. Pterygostomian regions with a row of teeth or spines. Ros- 

 trum long, the horns nearly straight, pubescent and divergent. Preorbital 

 spine prominent, acute, postorbital acute and pointing obliquelj' down- 

 wards. Basal antennal joint armed at its exteri!!fe,l angle with a slender 

 spine, the margin behind which is armed with two smaller spines. There 

 may be a few minute spinules at the apex of the eye-stalk. Merus of the 

 chelipeds furnished with small tubercles, which are more prominent on 

 the angles; carpus furnished with small tubercles on the outer side, which 

 are more or less plainly arranged in three or four rows; hands long, slen- 

 der, compressed, palm subcarinated above, nearly smooth, and generally 

 having a small tubercle on the outer side near the articulation; fingers 

 long and slender. Dactyls of the slender ambulatory legs long and nearly 

 straight. Abdomen of the male tapering from the third segment, the last 

 joint longer than broad and rounded at the tip. Abdomen of the female 

 broadly elliptical, the joints increasing in length from the third to the 

 last. In some females, either immature or sterile, the abdomen is narrowly 

 elliptical and not nearly so wide as the thoracic sternum. The legs and 

 many parts of the body are covered with a short pubescence. 



Miss Rathbuii, who has carefully studied a large 

 number of specimens of this species, gives the following 

 account of its variations: '' This species ranges from 57° 

 north latitude, off Kadiac, Alaska, to 32° north latitude, 

 of! San Diego, Calif., and in depth from 27 to 603^ 

 fathoms. It exhibits wide variations from Dana's types, 

 especially in more southern latitudes, where, as a rule, 

 the carapace is very much swollen at the branchial 

 regions, making the width much greater in proportion 

 to the length; the second and third joints of the antennae 

 are much more slender; the hepatic region is furnished 

 with a sharp spine; and, lastly, the tubercles of the 

 carapace are much more numerous and some of them 

 spinous. These characteristics, if uniform, would be 

 specific, but the two extremes intergrade to such an 

 extent as to render impossible even a varietal separa- 

 tion. The broad form is, with one exception, confined 



