20 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 
Cymopolia gracilis, sp. nov. 
This species, of which only one specimen has been obtained, resembles 
C. cursor, A. Milne-Edwards (Bull. Mus. Comp. Zool. Cambridge, viii, p. 
29, 1880), in the great length of the second pair of ambulatory legs, but 
is at once distinguished by the much smoother carapax without tubercles 
on the posterior margin, by the broad sinuses of the superior margin of 
the orbit, and by the conspicuously hook-shaped tips of the first pair of 
abdominal appendages of the male. 
Male.—The front is deeply divided by a sharp median sinus, and is 
slightly and obtusely bilobed either side, with the inner lobes much more 
prominent than the lateral. The orbit is very broad and open above. 
The superior margin is armed with two small teeth, separated from each 
other and from the inner and outer angles of the orbit by rounded 
sinuses, of which the inner is very broad and nearly semicircular ; the 
middle and outer successively smaller; the outer angle is triangular 
and a little less prominent than the outer suborbital lobe, which is 
dentiform and separated from it by a shallow sinus; and the inner sub- 
orbital process (which is also the dorsal wall of the efferent branchial 
passage) is narrow, rounded at the tip, reaches nearly as far forward as 
the lobes of the front, and is separated from the outer suborbital lobe 
by a very broad and rounded sinus. The antero-lateral margin is un- 
armed, except by a small dentiform tubercle on the anterior part of the 
branchial region in place of the sharp tooth in C. cursor. The dorsal 
surface of the carapax is naked, minutely granulated, and armed with 
a very few low and obtuse tubercles. There are three faintly indicated 
tubercles on the middle of the gastric region; two, the largest of all, 
surmount a transverse ridge on the anterior part of the cardiac region ; 
on either side, and nearly in line with these, are two smaller ones on 
the branchial region, above and back of the dentiform marginal tubercle 
already referred to; and in front of these two small ones there is a slight 
but scarcely tuberculiform elevation. 
The eyes are large, the greatest diameter equaling nearly a third the 
length of the carapax, reniform, and bear upon the upper side of the 
stalk, near the cornea, two or three minute elevations, which are much 
less conspicuous than the tubercles similarly situated in C. cursor. 
The chelipeds are slightly longer than the breadth of the carapax, 
and the chele are slender, naked, and nearly smooth, and the long, 
compressed, and very slender digits hooked at the tips and serrate 
along the prehensile edges. The first ambulatory leg is nearly twice 
as long as the breadth of the carapax, very slender, naked, and nearly 
smooth, except a very few minute granular tubercles near the base of 
the merus, and the dactylus is nearly as long as the propodus, sub- 
cylindrical, regularly tapered and slightly curved. The second ambu- 
latory leg is apparently more than twice as long as the first; the merus 
reaches nearly to the tip of the first leg, is tapered distally, and is 
armed with a few minute teeth near the distal end of the posterior edge 
