MARINE ISOPODA OF NEW ENGLAND, ETC. 421' 



Leptochelia algicola Harger. 



LeptocheUa Edwardsii Bate aud Westwood, Brit. Sess. Crust., vol. ii, p. 134, 1868 



{Tanais Edivardaii Kroyer?). 

 Tanaisfilum Harger, This Report, part i, p. 573 [279], 1874 (non Stimpson). 



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

 Paratanais algicola Harger, Am. Jour. Set., Ill, vol. xv, p. 377, 1878. 

 LeptocheUa algicola Harger, Proc. U. S. Nat. Mus., 1879, vol. ii, p. 102, 1879. 



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



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

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

 will, 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 x^lainly articulated, and are large in the males. The antennuloe 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 thii'd is slightly longer than 

 the second, and,insomesj)ecimens, present traces of a division into two 

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

 middle aud one or two more near the tip ; the second has also setce near 

 the tip, and the third bears a tuft of half a dozen or more set<« at the 

 tip. In the males (pi. XII, fig. 80) the antennula3 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 upw^ard ; the next two segments 

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

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

 segment. The antennae (j)l. XIII, fig. 84 Z>) in both sexes are short, 

 slender, and decurved, termmated by a tuft of sette. They appear to 

 vary but little in the family. 



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

 and carx)us 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. Xear the base of the lobe are usually two stout setie. The 

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

 especially in the last three segments; the carpus is elongate and 

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

 attaining the end of the basal antennular segment; the i)ropodus (pi. 

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

 digital i)rocess, bearing also two stout setae near the second tooth; 

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



