298 BULLETIN 100, UNITED STATES NATIONAL MUSEUM 
than the one on the right and reaching the center of the caudal rami. 
Urosome nearly half as wide as the metasome but less than a fifth 
as long and 2-segmented. Genital segment much larger than the anal 
segment and covered with an irregular dorsal carapace, which is 
widened posteriorly and extends backward to cover all the anal seg- 
ment and more or less of the caudal rami. In both Brady’s and 
Giesbrecht’s figures this dorsal carapace is widened but little pos- 
teriorly, and is armed on the dorsal surface with several processes and 
spines arranged irregularly, as seen in figure 422, and much of both 
caudal rami is visible dorsally. This was true of only two of the 
Albatross specimens; in all the others the entire left ramus was cov- 
ered and most of the right one, and in three specimens nothing could 
be seen of the rami from above. Again the posterior margin of this 
carapace is not uniform but varies considerably. In most of the 
specimens it was like that shown in figure 207 or the slight variation 
seen in figure 209, but in two females it was shaped as in figure 421, 
and in three others it had the scalloped margin seen in figure 423. 
The right caudal ramus is twice as large as the left and each is armed 
with five plumose setae. 
The first antennae are rather slender and reach the middle of the 
third thoracic segment. The exopod of the second antenna is slender 
and considerably shorter than the endopod. The maxillipeds are 
large and stout and armed with strong setae. The endopods of the 
first legs are made up of three segments, the first with one, the second 
with two, and the third with five inner setae. Each ramus of the 
fifth leg is 1-segmented, the exopod four times as long as the endopod, 
strongly curved inward, with four small spines on the convex margin 
and acuminate at the tip. The endopod is bifurcate for about one- 
third of its length and attached at an angle to the inner distal corner 
of the basipod. Total length 4.25 to 4.50 mm. Metasome, including 
the spines at the posterior corners, 4 mm. long, 0.90 mm. wide. 
Male.—Metasome similar to that of the female but narrower, more 
pointed anteriorly, and with nearly symmetrical spines on the pos- 
terior corners, reaching the posterior margin of the genital segment. 
Head separated from the first segment, its lateral hooks longer than 
those of the female and curved. Urosome less than a fourth as wide 
as the metasome and 5-segmented; Brady’s statement that it is 3-seg- 
mented is erroneous; it is perfectly symmetrical in strong contrast 
to the very irregular urosome of the female. The caudal rami are 
also symmetrical, more than three times as long as wide, and slightly 
curved, each with five setae, one of which is sometimes lengthened. 
The grasping (right) antenna is shown in figure 212 and corre- 
sponds to those figured by Brady and Giesbrecht. The other ap- 
pendages are like those of the female except, of course, the fifth legs. 
In the chela of the right fifth leg the movable finger is slender and 
