MARINE ISOPODA OF NEW ENGLAND, ETC. 421' 



Leptochelia algicola Harger. 



Leptochelia Edwardm Bate and Westwood, Brit. Sess. Crust., vol. ii, p. 134, 1868 



(Tanais Edwardsii Kroycr?). 

 Tanaisftlum Harger, This Report, jiurt i, p. 573 [279], 1874 (noti Stirapson). 



Verrill, This Report, part i, p. 381 (87), 1874. 

 Paratanais algicola Harger, Am. Jour. Sci.,III, vol. xv, p. 377, 1878. 

 Leptochelia algicola Harger, Proc. U. S. Nat. Mus., 1879, vol. ii, p. 1G2, 1879. 



Plates XII and XIII, Figs. 80, 83-86. 



The large and strong chelate claws, six-jointed pleon, and uropods 

 with a short, one-jointed, outer ramus and a six-jointed inner ramus, 

 win, in general, distinguish the present species from any other Isopod 

 on our coast. 



The body is of nearly uniform size throughout, and not constricted at 

 the articulations. The head is narrowed in front. The eyes are conspic- 

 uous and plainly articulated, and are large in the males. The antennulas in 

 the females (pi. XIII, fig. 84 a) are shorter than the head and first thoracic 

 segment, and are comi)osed of three segments, of which the first is longer 

 than the second and third together, and the third is slightly longer than 

 the second, and, in some specimens, present traces of a division into two 

 segments. The basal segment bears a short, stout seta just beyond the 

 middle and one or two more near the tip ; the second has also setae near 

 the tip, and the third bears a tuft of half a dozen or more setse at the 

 til). In the males (pi. XII, fig. 80) the anteuuulae are about two-thirds 

 as long as the body and usually eleven-jointed, but sometimes with one 

 or two segments more or less than that number. The basal segment 

 forms, in this sex, about one-third the length of the organ, and is curved 

 from near the base so as to be convex ujDward 5 the next two segments 

 decrease rapidly in length, and are followed usually by eight flagellar 

 segments provided with "olfactory setce" from two to four or more to a 

 segment. The anteuufe (pi. XIII, fig. 84 &) in both sexes are short, 

 slender, and decurved, terminated by a tuft of setae. They ai^ijear to 

 vary but little in the family. 



The first pair of legs have the merus triangular, bringing the ischium 

 and carpus together. In the female (pi. XIII, figs. 83 and 84 c) these 

 legs, in their natural position, extend but little beyond the head; the 

 proi)odus has a stout, digital process nearly in the line of its axis; 

 this process is broadly notched near the base, then elevated into a 

 slightly serrulate lobe, and bears at the apex a short, stout terminal 

 tooth. Near the base of the lobe are usually two stout setae. The 

 first pair of legs in the males are mucli larger and more elongated, 

 especially in the last three segments; the carj)us is elongate and 

 cylindrical, extending about half its length beyond the head, and 

 attaining the end of the basal antennular segment; the propodus (pi. 

 XII F, fig. 85) is robust and has a strong, curved, and two-toothed 

 digital process, bearing also two stout setae near the second tooth; 

 the dactylus is also curved and provided on its inner margin with 



