PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 433 



to N'ephrops. The stimctiire and arrangement of the branchiae wore 

 apparently not examined by Wood-Mason, but in our species they agree 

 with Xephrnps Xorvegicus^ there being nineteen branchioe upon each side, 

 arranged bke the nineteen posterior branchiae of each side of Ilomarus. 

 The brancliia of the second maxilliped is wholly M^anting, unless it is 

 represented by a minute, papilla-like process near the base of the epi- 

 gnath. The oral appendages agree perfectly with those of Nephrops Nor- 

 rcgicus. The densely pubescent chelipeds, however, are very different 

 from the naked and carinated chelipeds of Nephrops, and probably afford 

 an additional generic distinction. 



Axius armatus, sp. nov. 



Female. — The carapax is strongly compressed, about twice as long as 

 high, smooth and nearly naked. The rostrum is narrow, acuminate, 

 spiniform at the tip, and armed along each edge with four or five slen- 

 der, acute, and spiniform teeth, directed forward and slightly upward. 

 From the edge of the rostrum a sharj) lateral carina runs back on each 

 side more than a third of the way to the cervical suture. The dorsal 

 carina is sharp anteriorly, extends back nearly to the cervical suture, 

 but anteriorly only as far as the posterior marginal teeth of the rostrum, 

 and is armed with two spiniform teeth just back of the base of the ros- 

 trum. About half way between the dorsal and lateral carinas there is 

 a very distinct subdorsal carina, parallel with and extending back nearly 

 as far as the dorsal, and in front turned abruptly inward opposite the 

 posterior dorsal tooth, but not quite reaching the dorsal carina. 



The eyes are small and black. 



The peduncle of the antennula reaches by the tip of tlie rostrum the 

 full length of the last segment, and the flagella are subequal in length 

 and about as long as the carapax. The third segment of the peduncle 

 of the antenna is armed with a slender spine on the lower side of the 

 distal end. The distal spine on the second segment, at the base of the 

 acicle, is slender, acute, and more than half as long as the rest of the 

 segment, while the acicle is slender, straight, and as long as the fourth 

 segment, which is slender, and about as long as the second segment to- 

 gether with its distal spine. The fifth, or last, segment is not more than 

 a third as long as the fourth. The flagellum is more than twice as long 

 as the caraj)ax. 



The merus of the external maxilliped is armed at the distal extremity 

 of the lower edge with two very long and slender spines. 



The larger cheliped is about twice as long as the carai^ax, and the 

 chela itself, to the tip of the dactylus, is nearly as long as the carapax. 

 The propodus is strongly compressed, about half as broad as the entire 

 length and three-fourths as broad as the length of the basal jiortion, 

 which is convex on both sides and has the edges sharp and carinated. 

 The digital portion is longitudinal, about three-fourths the entire length, 

 more than half as long as the basal portion, slightly upturned at the tip, 

 Proc. Nat. Mu3. 80 28 Jan. 1 0, 1 8 8 1 . 



