170 



BULLETIN 91, UNITED STATES NATIONAL MUSEUM. 



Dactylus transverse, a tubercle at middle of prehensile margin which 

 fits against margin of propodus. 



First and second legs narrow, second longer, larger, and reaching 

 extremity of propodus of third pair. Merus of third pair very 

 little dilated at middle. Fourth pair reaches middle of carpus of 

 third pair. 



Sides of male abdomen ffom third to fifth segments, inclusive, 

 converge regularly ; those of sixth segment still more convergent, seg- 

 ment very short; terminal segment narrowest, broader than long, 

 rounded. 



Measurements. — Female holotype, length of carapace 6.6, width of 

 same 12.5 mm. Male (21593), length of carapace 5.5, width of 

 same 11 mm. 



Fig. 108. — Pinnixa bkevipollex. a. Outer maxilliped of female holotype, X 181 ; 



h, ABDOMEN OF MALE (21593), X 71. 



Materiol examined. — Off Gulf of San Matias, Patagonia ; lat. 42° 

 24' 00'' S.; long. 61° 38' 30" W.; 43 fathoms; dk. S. bk. Sp.; Jan. 

 14, 1888; station 2768, Albatross; 1 male, 2 females (1 female holo- 

 type). Cat. No. 21593, U.S.N.M. 



Genus SCLEROPLAX Rathbun. 



Scleroplax Rathbun, Proc. U. S. Nat. Mus., vol. 16, 1893, p. 250; type, 

 /S. granulata Rathbun, 



Carapace transverse, subpentagonal, hard, very convex, regions 

 scarcely indicated, lower or true antero-lateral margin curving grad- 

 ually into postero-lateral margin, not forming an angle with it as in 

 Pinnixa. Ambulatory legs similar, third longest but not unusually 

 long, fourth not noticeably reduced. Ischium of outer maxillipeds 

 rudimentary, merus oblique, palpus three-jointed, the last joint 

 articulating near proximal end of preceding joint. 



Only a single species known. 



