152 STALK-EYED CRUSTACEA. 
one begins at the orbit and runs backward and then obliquely upward to the 
hind border of the carapace. It is separated anteriorly from the base of the 
external orbital spine by a deep but narrow groove. The inferior lateral 
carina is continuous in front with the inferior (branchiostegal) spine of the 
anterior margin of the carapace. It trends backward nearly parallel with 
the superior lateral carina, and becomes obsolete a little way from the hind 
margin of the carapace. A smaller carina runs close to the lower margin of 
the carapace. 
The first, second, and sixth segments of the abdomen are not carinated. 
The third, fourth, and fifth segments are carinated along the median dorsal 
line. On the third segment the carina is broken into two moieties, the ante- 
rior of which is fluted above and terminates in a sharp spine a little behind 
the middle of the segment, while the posterior portion is rounded above and 
ends in a spine on the posterior border of the segment. The carina on the 
fourth and fifth segments is unbroken, and ends in a longer spine at the pos- 
terior border of each of these segments. Thus there are four spines in the 
median dorsal line of the abdomen, two on the third segment, one on the 
fourth, and one on the fifth. 
The telson ends in a long, acute, median tooth, which is flanked by two 
pairs of movable spines. Of these thé distal exceed the median tooth in 
length; the proximal, on the contrary, are very small and short. There 
are, moreover, three pairs of spines on the dorsal surface of the telson. 
The basal segment of the antennule is furnished with a long external 
spine (stylocerite) which reaches nearly to the end of the second segment of 
the antennule. At the base of this spine, against the eye-stalk, is a rounded 
lobe. 
The antennx are twice the length of the whole body, including the 
rostrum. The antennal scale reaches nearly half way to the end of the 
rostrum ; its external lateral tooth is situate some distance behind the front 
extremity. 
The third maxillipeds bear a rudimentary exopod hardly a fifth as long 
as the ischium. 
The carpus of the right leg of the second pair is composed of ten seg- 
ments ; on the left leg of the same pair the carpus contains from twenty-two 
to twenty-seven segments. 
Dimensions of a male: length from tip of rostrum to end of telson, 
197 mm.; length of rostrum, 70mm. ; length of carapace, including rostrum, 
