278 BULLETIN 100, UNITED STATES NATIONAL MUSEUM 
on segments 5, 8, 11, 18, 18, and 23. In the second antennae the 
exopod is much longer than the endopod and the end segment is 
longer than the second segment. The mandible (fig. 387) has two 
large acute teeth on the narrow chewing blade, the outer one longer 
than the inner. The palp is biramose, the rami well separated, the 
endopod 2-segmented, the exopod 4-segmented. The maxilliped is 
7-segmented, the basal segment with three setae on the outer margin, 
the second segment with three setae on the inner margin, and the five 
end segments very short, each with two large setae on its inner margin, 
curved and plumed on the concave side only. The exopod of the first 
leg is distinctly 3-segmented; Esterly said it was 2-segmented with 
an extra spine on the basal segment; Scott did not mention it, but 
his figure shows three segments. Total length 7 mm. 
Male—Metasome similar to that of the female but proportionally 
shorter and wider; head separated from the first segment with the 
rostrum turned ventrally almost at right angles to the body axis. 
Fourth and fifth segments fused with a similar tuft of hairs at the 
tip of the curve. Urosome longer than in the female, half as long as 
the metasome if the caudal rami are included and made up of five 
segments. These diminish in length distally, but the first four are 
about the same width; the anal segment 1s much shorter and nar- 
rower. The caudal rami are longer than the anal segment and one- 
half longer than wide. 
The first antennae are shorter than in the female and do not quite 
reach the urosome, and neither of them is geniculate. The second an- 
tennae and mouth parts correspond to those of the female with similar 
mandibles and maxillipeds. The exopod of the first leg is also dis- 
tinctly 8-segmented. The fifth legs are large and reach beyond the 
tips of the caudal rami (fig. 385). The second basipod of the right 
leg is considerably swollen, and the exopod is 2-segmented, the end 
segment as long as the basal and bluntly rounded at its tip. The 
endopod is 1-segmented and as long as the basal exopod segment; 
the distal half is flattened and somewhat twisted. The left leg is 
4-segmented and made up of two basipod and two exopod segments 
with no trace of an endopod. Neither basipod segment is swollen, 
but the first exopod segment is enlarged on its inner margin. The 
end segment is widened at its tip and the terminal armature is rather 
complicated, as seen in enlarged detail in figure 389. Total length 
6.75 to 7 mm. 
Allotype male——U.S.N.M. No. 74127; station 4588, latitude 19°52’ 
N., longitude 106°02’ W., southwest coast of Mexico. 
Remarks.—The fingerlike processes on the ventral protuberance of 
the genital segment in the female are plainly visible in lateral and 
