PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 433 
to Nephrops. The structure and arrangement of the branchise were 
apparently not examined by Wood-Mason, but in our species they agree 
with Nephrops Norvegicus, there being ieicerl branchi upon each side, 
arranged like the nineteen posterior branchiz of each side of Homarus. 
‘The branchia of the second maxilliped is wholly wanting, 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 N ephrops Nor- 
vegicus. The densely pubescent chelipeds, however, are very different 
from the naked and carinated chelipeds of Nephrops, ated 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 sharp lateral carina runs back on each 
side more than a third of the way to the vervieal 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 carine there is 
avery 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 the 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 carapax. 
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 carapax, 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 portion, 
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, 
Proce. Nat. Mus. 80-——28 Jan. 10,1881. 
