156 BULLETIN 100, UNITED STATES NATIONAL MUSEUM 
Urosome half as wide and almost half as long as the metasome and 
made up of three segments. Genital segment as long as the two 
abdominal segments combined, its lateral margins convex. Basal 
abdominal segment twice as long as the anal segment, also with convex 
sides. Anal segment wider than long with straight sides, incised at 
the center of the posterior margin. 
First antennae slender, just reaching the posterior end of the thorax 
and rather sparsely setose. Exopod of second antenna scarcely longer 
than the basal segment of the endopod. Mandible with one large 
acute outer tooth separated from the others and a row of smaller teeth 
across the end diminishing in size inwardly. First four pairs of 
legs biramose, exopods 3-segmented, endopods 2-segmented, much 
shorter than the exopods. Fifth legs uniramose, 3-segmented, basal 
segments totally fused across the midline. Middle segments sub- 
rectangular and slightly curved, with a large plumose seta at the 
outer distal corner. Third segments globular at the base and then 
narrowed into a long acuminate curved blade, which is perfectly 
smooth. Total length 2.25 mm. Metasome 1.66 mm. long, 0.65 mm. 
wide. 
Male.—Metasome elongate-elliptical as in the female, not quite three 
times as long as wide, narrowed a little anteriorly but scarcely at all 
posteriorly. Head separated from the first segment and about as 
long as the thorax; fourth and fifth segments fused with rounded 
posterior corners. Urosome half as long but only a third as wide 
as the metasome and 4-segmented. Genital segment wider than the 
abdomen, with strongly convex lateral margins, making it a little 
wider than long. Basal abdominal segment flask-shaped, the en- 
larged distal end with convex sides; middle and anal segments with 
straight sides and as wide as the neck of the flask. Caudal rami one- 
half longer than wide and nearly as long as the anal segment. 
First antennae reaching the middle of the genital segment and even 
more slender than in the female, neither one geniculate. Second an- 
tennae, mouth parts, and first four pairs of legs like those of the 
female. Fifth legs uniramose, 4-segmented, and relatively long and 
slender. Basal segment of the right leg bent at right angles, the 
second segment with a long seta on the posterior surface at about the 
center, the third segment with a large triangular process on the inner 
margin, the fourth segment curved into a half circle, with a small 
terminal seta and another near the center of the concave margin. 
The basal segment of the left leg is very short and has a short seta 
at the inner distal corner. The second and third segments each carry 
an outer seta, while the fourth segment is split and each portion is 
tipped with a large terminal seta. Total length 2.10 mm. Metasome 
1.25 mm. long, 0.41 mm. wide. 
