488 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



lateral processes by a distiuct interval. Terminal joiut of palpus very- 

 slender. Tarsus longer than the propodus. Auxiliary claws nearly 

 two-thirds the dactylus. 



Body very smooth and rather robust, for the genus, with the lateral 

 processes separated by an inter-space about equal to their width. 

 Oculiferous segment constricted, so as to form a short and narrow neck, 

 nearly as in the preceding species; there is a slight, though distinct, 

 interval between the process bearing the accessory legs and that of the 

 first pair of ambulatory legs. Above, there is a distinct sulcus running 

 backward from midway between the bases of the antennae. Oculiferous 

 tubercle acutish, prominent, situated just anterior to the first pair of 

 lateral processes ; eyes large, ovate, light colored, surrounded by dark 

 pigment. Posterior segment narrow with the lateral processes directed 

 backward; abdomen slender and tapering, distinctly bifid. 



Eostrum about as long as the oculiferous segment, nearly cylindrical, 

 shghtly swollen in the basal half. Antennee extremely slender — more 

 so than in any other species of the genus known to me ; basal joint 

 somewhat longer than the rostrum ; chela much elongated; claws, when 

 closed, crossing each other at a considerable distance from their tips. 

 Both claws are armed with a dense row of spines, which gradually de- 

 crease in length toward the tips, and finally disappear, leaving the 

 terminal portion bare for some distance; these spines are larger and 

 more crowded on the movable claw; on the other, larger spines 

 alternate with from one to three smaller ones. In one specimen there 

 were 109 such spines upon the movable claw and ISl upon the other. 



Palpi with a very short and stout basal joint, about one-sixth or one- 

 seventh as long as the second ; the third is considerably less than the 

 second, the fourth still shorter, the terminal one less than the fourth 

 and extremely slender and straight. The entire appendage is slightly 

 hairy. 



Accessory legs resembling those of iV^. grossijpes; in the male they are 

 considerably longer than in the female, the fifth joint is more slender 

 and elongated, and with a strong s-shaped curvature. The outer joints 

 bear a few scattered hairs. 



The legs are very slender, especially the outer four joints, and sparsely 

 hairy; the proportions of the joints are about as in If. longitarse, but the 

 tarsus is only about 1^ times the propodus ; both these joints have a 

 close and pretty regular series of small, slender spines along the entire 

 inferior margin. Dactylus slender and acute, rather more than half 

 the proi^odus ; auxiliary claws very large, nearly two-thirds the dactylus. 



Color in alcohol, light yellowish- white. Length of a large specimen 

 9.3 millimeters. Extent 72 millimeters. 



This species is very distinct, and the specific characters appear to 

 vary but slightly. It is, in general appearance, much like X. Strdmii, 

 but may be at once distinguished by the large auxiliary claws. The in- 

 terval between the accessory legs and the first pair of ambulatory legs 



