50 PROCEEDINGS OF UNITED STATES NATIONAL. MUSEUM. ; 
and the distal extremities of the ambulatory legs to very near the bases 
of the propodi, which parts were white, the color stopping on each of 
these appendages very suddenly at the point where they cease to be 
armed with spines. All the other specimens show more or less distinct 
indications of the same coloration. 
Anoplonotus politus, gen. et sp. nov. (Pl. 2, Fig. 1; Pl. 3, Figs. 1-5a.) 
Excluding the rostrum, the carapax is nearly as broad as long; includ- 
ing the rostrum, seven to eight tenths as broad as long, the rostrum 
being rather less than a fourth of the entire length. The rostrum is 
vertically flattened, though obscurely carinated longitudinally above, 
horizontally triangular, but not acute at the tip, and slightly curved 
downward distally. There are no spines or tubercles upon the carapax, 
but the gastrie region is somewhat protuberant and separated from the 
branchial regions by a broad sulcus each side, and from the prominent 
cardiac region by a still deeper sulcus which extends either side as a 
shallow sulcus across the branchial region, which is again crossed by a 
narrower sulcus in front, but the cardiac region is not conspicuously 
separated from the branchial region either side of it. The orbital por- 
tion of the anterior margin is narrow and advanced considerably in 
front of the antero lateral angles, which are formed by the hepatic 
regions and are nearly right-angular. The lateral margins are slightly 
curved, and the greatest breadth is a little back of the middle. The 
surface of the carapax is granulose, particularly along the sides, where 
the granules are arranged in transverse lines. 
The small eyes are partially beneath the rostrum, and scarcely reach 
its middle; there is a slight protuberance on the outer side of the stalk 
near the base; and the eye itself is semitranslucent in the alcoholic 
specimens; its diameter is rather less than that of the stalk and about 
half the whole length, and the cornea is apparently entirely without 
facets. 
The basal segment of the peduncle of the antennula is a little shorter _ 
than the rostrum, about three-fourths as broad as long, somewhat 
swollen on the outer side, and armed with two teeth at the distal extrem- 
ity. The second and third segments are slender, subequal in length- 
and each searcely as long as the basal. The upper flagellum is about | 
as long as the distal segment of the peduncle, the basal portion swollen 
and composed of numerous short segments, while the distal portion is 
very slender and composed of about five elongated segments. The lower 
flagellum is little more than half as long as the upper, slender through- | 
out, and composed of about three segments. The peduncle of the an- 
tenna arises just outside the peduncle of the antennula and at some 
distance from the antero-lateral angle of the carapax, scarcely reaches — 
the tip of the rostrum, and its three distal segments are slender. The 
flagellum is very slender, and reaches to about the tips of the cheli-— 
peds. | 
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