4 Mr. C. Chilton on a new Species of 
of the pereion; on each side it is deeply notched for the 
insertion of the antennz ; it is produced in front between the 
antenne and has the front margin, to which the upper lip is 
attached, straight, with the lateral angles well rounded. The 
lateral portion behind the bases of the antennee has the ante- 
rior angle somewhat acute and the posterior angle produced 
and rounded and bearing the large eyes, which are thus some- 
what pedunculated, though apparently not so much so as in 
some other species of the genus. 
The pereton (Plate I. fg. 1) has the first segment a little 
broader than the head, rather shorter than the second, the 
second, third, and fourth subequal in length, widening slightly 
up to the fourth segment, which is the widest; the fifth, 
sixth, and seventh segments are progressively shorter and 
curve backwards at the sides into rounded lobes, which are 
somewhat gaping laterally. 
The pleon (Plate I. fig. 1) is much narrower than the 
pereion, somewhat conical or pear-shaped, rapidly narrowing 
posteriorly, with the extremity rounded. It usually projects 
slightly upwards, and the uropoda are barely visible in a 
dorsal view. 
The antennules (inner antenne) (Plate I. figs. 2 and 3) reach 
somewhat beyond the end of the third joint of the peduncle 
of the outer antenne. ‘The first or basal joint is the broadest, 
being about two thirds as broad as long; the second joint is 
about as long as the first, but only half as broad at the base ; 
it expands considerably towards the distal end and bears a 
few fine sete scattered over the surface; the next two joints 
are subequal, small, the two together being less than half the 
length ot the second joint; each is nearly as broad as long, 
they are followed by a long slender joint as long as the 
second and third together; at the extremity of this are two 
very small joints provided with long “ olfactory filaments.” 
In the possession of the long slender joint at the end of the 
antennules ihis species resembles Munna Whiteana, Spence 
Bate and Westwood*. It is evidently, however, subject to 
some variation, for I have one specimen in which the right 
antennule is of the normal shape, as already described, but 
the left one has the long fifth joint only about two thirds as 
long as that on the right, while the following joint is much 
larger than usual, being about one half the length of the fifth 
joint; both of these bear “ olfactory filaments,” so that 
doubtless the long fifth joint should be looked upon as a 
modified portion of the flagellum. 
* ‘ British Sessile-eyed Crustacea,’ i, p. 829, 
