114 BULLETIN OF THE 



mark. In the young, the horns of the rostrum are more divergent than in 

 the adult, and the anterior branchial spine is smaller. The feet are pro- 

 vided with a few long, thick hairs not found in the adult. 



Off the Quicksands, January 23, 1809. Cast No. 1. 34 fathoms. 



Tiarinia setirostris nov. sp. 



Carapax narrow, with perpendicular sides. The greatest breadth, 

 which is at the posterior fourth of the post-frontal length, is only one 

 fourth greater than the transorbital breadth. The upper surface is naked, 

 and bears a few small tubercles, of which three, in a median line on the 

 posterior half of the carapax, are larger than the others. The posterior 

 tubercle, on the intestinal region, is spiniform and curved upward. Sides 

 of the carapax somewhat setose. Rostrum half as long as the post-frontal 

 part of the carapax, with the horns slightly gaping near the base, but con- 

 tiguous for the remainder of their length, very slender, setiform, and setose. 

 External antennae as long as the rostrum ; basal joint concave, without 

 any spine at the antero-external angle ; flagellum long, hair-like. Cheli- 

 peds in the male large, longer than the carapax including the rostrum ; 

 hand somewhat compressed, granulated above ; fingers very short, widely 

 gaping. Ambulatory feet long, slender, and smooth ; those of the first 

 pair nearly as long as the chelipeds. 



Dimensions of a male specimen : Length of carapax, 0.82 ; breadth, 

 0.35 inch. 



This species differs much from the typical Tiariniac in the great length, 

 slenderness, and smoothness of its ambulatory feet, and future investiga- 

 tions, on more abundant materials, than those at present available, may 

 prove it to be generically distinct; in which case I would propose for it 

 the name Leptopisa. 



The Tiariniae hitherto described all belong to the Indo-Paeific fauna, 

 living chiefly in the southern part of the Japanese Archipelago, in the 

 seas of Sulu and the Philippines, Nicobar, etc. Of these species our 

 Florida form approaches nearest to T. anrjusta Dana, which it resembles 

 in the narrowness of the carapax, but from which it is at once distinguished 

 "by the less tuberculated carapax and slender feet. 



It was taken at the following points : — 



Key West, 2 to 5 fathoms. 



Near the Tortngas, 9 fathoms. 



On the Fishing Ranks, S. W. of Loggerhead Key. 



Subfamily NAXIINAE. 



The characters of the orbital region in Chorinus are so different from 

 those of Naxia and its allies as to forbid its being placed in the same sub- 



