266 SPECIFIC DESCRIPTION. 
point. The dorsal surface is tolerably smooth, 
exhibiting but faintly the markings of the internal 
viscera. The eyes are small, and reach but little 
beyond the orbital margin. The external 
antennze have the first joint fused with the cara- 
pace, the second and third compressed and arcu- 
ate, and terminate in a smooth flagellum. 
The first pair of pereiopoda are moderately 
long, having the meros triangulate, the upper angle 
forming a prominent carina, that extends along 
but terminates abruptly a little short of both 
extremities of the joint; the carpus is tricarinated ; 
the propodos is laterally compressed, and forms 
about half the length of the limb, and is about 
one-third its breadth. The dactylos is slightly 
curved and slightly serrated on the inner margin, 
and antagonises at the extremity with the pro- 
duced propodos. The second pair of pereiopoda 
are nearly as long as the first, but much more 
slender, having the meros and propodos subeari- 
nated. The three posterior pairs are shorter. 
The pleon is small and narrow, the second and 
third segments being the broadest; while the 
seventh is abruptly narrower than the sixth, and 
forms a triangular plate. The female differs 
from the male in being more protuberant over 
the stomachal region, and consequently the ros- 
