ISOPODS OP NORTH AMERICA. '23 



ANALYTICAL KEY TO THE SPECIES OE THE CENUS LEPTOCHELIA. 



a. Outer ])raiu;h of uroixxla composed of two a.ri\c\iiii. .LepUjcheU a forr est i (Stebbing) 

 a\ Outer branch of iiropoda composed of one article. 



h. Inner branch of uropoda composed of iii-x.a.riu'\Qii..LeptocheUa sangniji (Kr0yer) 

 ¥. Inner liranch of uropoda composed of less than six articles, 

 c. Inner branch of uropoda composed of five articles. 



d. First pair of antennae in male with basal segment about one-third the 

 length of organ, or about two-thirds as long as the body. Chelipeds in 

 male with digital process of propodus armed with two teeth. Carpus 

 extends to the extremity of basal article of first pair of anterma. 



Leptochelia dubia (Kr0yer) 

 d^. First antenme in male with basal article one-half the length of entire organ. 

 Chelipeds in male with digital process armed with one low, obtuse tooth 

 near the base and one more prominent one near the tip. Carpus of 

 chelipeds more than half the length of the body, longer than the 

 peduncle of the first antenme and about half as long as the body. 



Leptochelia rapax Harger 

 (/. Inner branch of uropoda (lomposed of three or four joints. 



Leptochellaf filuin (Stimpson) « 



LEPTOCHELIA FORRESTI (Stebbing). 



Dolichochella forresti Stebbing, Ann. Mag. Nat. Hist. (6), XVII, 1896, pp. 49-56. 

 Leptochelia mbmta Stebbing, Ann. Mag. Nat. Hist. (6), XVII, 1896, pp. 156-160.— 



Richardson, Proc. U. S. Nat. Mus., XXIII, 1901, pp. 503-504. 

 Leptochelia forresti STEBBiN(i, Willey's Zool. Results, 1902, p. 615. 



Locality. — West Indies. 



Depth. — Shallow water. 



"The front marghi of the head shield projects but slightlj^, forming 

 a very obtuse angle, the corners being shallowly excavate for the 

 ocular lobes. The part of the shield to which the first gnathopods (or 

 chelipeds) are attached is wider than the front. The pleon at its base 

 is as wide as the trunk, but narrows distally with a gentle curve; the 

 sixth segment, which is very little longer than that preceding it, ends 

 in an obtuse angle similar to that of the frontal margin. 



"The eye lobes have a convex outer margin and are not very 

 sharph^ pointed in front. The pigment is black in the mounted 

 specimen. 



''''First antennm. — These are as long as the animal from the front of 

 the head to the apex of the pleon. The first joint is dilated at the 

 base, for the rest slender, its length forming two-fifths of the wdiole 

 antenna. The second joint is rather less than three-fourths the 

 length of the first. The third is a fifth of the length of the second, 

 and so slender as to look like a part of the fiagellum, among the eight 



<*The uropoda are described as four to five jointed. If the peduncle is counted as 

 the first one of these the branch is then three to four jointed. Nothing is known of 

 the outer branch, but in the table I have placed it with those species in which the 

 outer branch is one-jointed, as this is the case with the larger number of species 

 in this genus. 



