296 BULLETIN 100, UNITED STATES NATIONAL MUSEUM 
one on the right wider and longer than the one on the left, nearly 
reaching the posterior margin of the genital segment. The posterior 
ends of the pads are broadly rounded with a minute spine at the very 
tip, which is easily overlooked. 
The urosome is 3-segmented and very asymmetrical; the dorsal sur- 
face of the genital segment is produced to the left and backward into 
a curved spine, which nearly reaches the tip of the caudal ramus. On 
the right side of the segment and nearer the posterior margin is a 
short blunt process curved over ventrally, and usually concealed in 
dorsal view by the right pad at the corner of the thorax. This pad 
and the genital segment were separated under pressure, bringing this 
process into view dorsally, as in figure 532. On the left side is a 
rounded process projecting to the left and covered in dorsal view by 
the left pad at the corner of the metasome. Both pads were removed 
for the drawing in figure 245. The basal abdominal segment is much 
larger than the anal segment, with an angular process at the center 
of the right side and a rounded process at the anterior corner of the 
left side. The anal segment is about half as long and wide as the 
basal segment, and its dorsal surface is produced backward over the 
bases of the caudal rami in a 38-lobed process which reaches the 
center of the rami. The latter are longer than wide and the left one 
is a little larger than the right. 
The first antennae reach the center of the last thoracic segment and 
are very slender but moderately setose. The exopod of the second 
antenna is a little shorter than the endopod and considerably narrower. 
The chewing blade of the mandible has a long conical tooth at the 
outer corner, then a shorter spherical tooth tipped with a spine, fol- 
lowed by three triangular teeth, the first two bifid at the tip. The palp 
has an exceptionally long basal portion and two short rami, each made 
up of asingle segment. The endopod of the first leg is 3-segmented, of 
the second, third and fourth legs 2-segmented. The fifth legs are 
slender, the exopods twice as long as the endopods and each ramus 
i-segmented. ‘The endopods are bifurcate at their tips, the inner 
branch longer than the outer. Each exopod has three spines at its 
tip, the middle one the longest, and a small spine on the outer margin 
near the center. Total length 3.75 mm. Metasome, excluding pads, 3 
mm. long, 1.12 mm. wide. 
Male.—Metasome proportionally narrower than in the female; head 
with similar flanges on each side armed with lateral hooks. Posterior 
corners of the last thoracic segment very asymmetrical, on the left 
side a pad similar to those in the female, on the right side a long and 
slender spine reaching back to the center of the antepenultimate seg- 
ment of the abdomen. The genital segment is considerably enlarged 
and is produced outward on the right side at the posterior corner into 
a short process cleft at its tip. The abdomen is 4-segmented and nar- 
