PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 1G3 



Rev. A. M. JsTormaii, appears to agree perfectly with the males of this 

 species, though not with Kroyer's description of Tanais Edward.sii. I 

 have uot therefore united my species with his, though I think it possi- 

 ble they may prove identical. 



The species occurs in considerable abundance at Noank Harbor, Conn., 

 among algte, and also at Vineyard Sound, and will probably be found 

 at other localities on the southern shore of Kew England. It has also 

 been collected by Professor Verrill, during the present summer, at Pro- 

 vincetown, Mass., in company with Limnoria and Chelura, in old piles. 



The genus Lepfochelia has several years' priority over ParatanaiSy and, 

 though founded on the male sex, ought, as I think, to be retained. 



Leptochelia Uimcola^ FarattmaisUmicoIaTlaTga'T, Am. Jour. Sci., Ill, vol. xv, p. 378, 



1878. 



Massachusetts Bay, off Salem, 48 fathoms, mud. 

 Leptochelia rapax, ii. s. 



Females of this species considerably resemble those of L. Umicola, 

 but may be distinguished by the following characters : The eyes are 

 larger and more conspicuous; the last segment of the anteunulse is 

 scarcely longer than the preceding, instead of nearly twice as long, as in 

 L. Umicola; the dactylus of the second pair of legs is somewhat shorter 

 and the terminal spine less attenuated, and the external ramus of the 

 uropods consists of a single very short and small segment, shorter than 

 the basal segment of the inner ramus, which is not elongated. The inner 

 ramus is five-jointed, instead of six-jointed, as in L. alrficola. 



The males are remarkable for the long and slender prehensile hand 

 terminating the first pair of legs. The body of the males is short and 

 robust, with the segments well marked by constrictions. The head, 

 with the united first thoracic segment, is short and rounded, bulging 

 strongly at the sides just behind the eyes, which are conspicuous, some- 

 what less in diameter than the bases of the antennulce, distinctly articu- 

 lated, and coarsely faceted. The antennulse are elongated, especially in 

 the basal segment, which is more than one-third as long as the body, 

 slightly swollen on the inner side, near the base, then tapering to the 

 tip ; the second segment is cylindrical, less than half as long as 

 and more slender than the first ; the third is less than half the 

 length of the second, and is followed by about eight short flogellar seg- 

 ments, the last one tipped with setaj. The antennse, when extended, do 

 not attain the end of the basal antenuular segment ; the first three seg- 

 ments are short, the fourth longest, being longer than the first three 

 together, the fifth slender and tipped with setai. The terminal setiB 

 of both antennulse and antennoe arise in part from minute or rudimen- 

 tary terminal segments. The first pair of legs forms the most striking 

 feature of this species. These legs, when extended, are in general 

 longer than the body of the animal, though they vary considerably 

 in size, being usually pro])ortionally smaller in the smaller specimens. 

 In these legs, the segments preceding the carpus are short and robust; 

 but the carpus is about half as long as the body, and the propodus 



