114 BULLETIN 97, UNITED STATES NATIONAL MUSEUM. 



Abdomen of male suboblong, distally tapering, at base not more 

 than half the width of the sternum ; sutures faint, except that mark- 

 ing the subtriangular terminal segment. 



Measurement!^. — Male holotype, length of carapace 1, width of 

 same 1.3 mm. 



Locality. — Known only from the type-locality, given above. 



Remarks. — This species is much narrower than any other Para- 

 pinnixa, and its eyes much larger. It is possible that the tiny 

 specimen represents a postlarval stage of an unknown adult ; that is, 

 a stage having a crab form, but not the adult form; this idea seems 

 to be indicated (1) by its small size; (2) by the eyes, large in pro- 

 portion to the size of the body, as in most zoeae and megalops; 

 (3) by the feathery ornamentation of the legs and carapace, which 

 assist in maintaining a pelagic existence; and (4) by the thin pre- 

 hensile edges of the fingers, which suggest that in another molt or 

 two they might disappear and leave narrow, gaping fingers. 



Genus DISSODACTYLUS Smith. 



Dissodactylus^SMiiia, Trans. Connecticut Acad. Arts and Sci., vol. 2, 1870, [>. 



172; type, D. nitidus Smith. 

 EchinopMlvs Rathbun, Amer. Nat., vol. 34, 1900, p. 590; type, E. melUtae 



Rathbun. 



Carapace broader than long, pentagonal, broad behind, broadest. 

 at antero-lateral angles; surface not areolated; front narrow, hori- 

 zontal, its margin continuous with arcuate antero-lateral margins. 

 Eyes minute, superior margin of orbit slightly or not at all emargi- 

 nate. Antennules transverse. Epistome usually very short, so that 

 the labial border approaches very near the front, leaving only a 

 narrow space, which is nearly filled by the antennulae. The labial 

 border is not interrupted in the middle by any projection or emargi- 

 nation and is continuous with lateral margin of buccal area. Palate 

 without longitudinal ridges. 



Ischium and merus of maxillipeds coalescent; palpus composed 

 of two or three segments, the dactylus, when present, small. 



Chelipeds of moderate size; fingers longitudinal. 



The ambulatory legs are small and differ little in length; dactyli of 

 three anterior pairs bifurcate, those of posterior pair usually simple. 

 In the male the sternum is flat and very broad, breadth between 

 posterior legs much more than twice as great as breadth of basal 

 segments of abdomen. 



Male abdomen narrow and only three-jointed, the first and second 

 segments anchylosed, and the third, fourth, fifth, and sixth also 



