568 Prof. A. Alcock 07i a neio Species of 



Cymonomus andamanicus, sp. n. (Plate XVIII.) 



The entire surface of the body and of all the exposed parts 

 of its appendages, except the terminal joint of the antennular 

 ])cdunclcs, is finely frosted. 



Carapace slightly, though manifestly, broader behind than 

 in front, without any marginal spinules ; the lateral borders 

 are ill-defined posteriorly, and the posterior border is eon- 

 cave in the middle line ; the usual regions and furrows are 

 rather faintly indicated. 



llostruin triangular, acute, reaching to the middle of the 

 eye-stalks : the frontal border on either side of it is advanced 

 beyond the antcro-lateral angles of the carapace, but the 

 subantcnnal tooth, which is so conspicuous in C. (juadratns, 

 is small and quite invisible in a dorsal view, though plain 

 enough in a side view. 



The eye-stalks, which are rigidly fixed, divergent, and 

 slightly curved, are devoid of hairs and enlarged spinules 

 and do not reach the tip of the antepenultimate joint of the 

 antennal peduncle ; the eye is a small, smooth, unpigraented, 

 subterminal patch. 



The antennules are stout, and their peduncle is more than 

 three-fourths the length of the carapace. 



The antennae are shorter and slenderer than the anten- 

 nules ; their peduncle does not reach the terminal third of 

 the second joint of that of the antennules, and none of its 

 joints are spinose; their lash is rather more than half the 

 length of the carapace. 



The gap between the epistome and the anterior end of the 

 external maxillipeds is singularly wide and almost sub- 

 tubular; on either side of the epistome is a spinule which 

 may, perhaps, serve to separate the inhalant from the 

 exhalant currents. The epipodite of the first maxilli])eds is 

 broadly foliaceous. 



The chelipeds of the male are equal, about half again as 

 long as the carapace, and not very massive ; a spinule at 

 the inner angle of the wrist and a few on the upper border 

 and outer surface of the hand are enlarged ; the hand is 

 longer than the ischium and racrus combined, the fingers 

 are slightly longer than the palm and their cutting-edge is 

 entire. 



The first pair of true legs are about 3 times, the second 

 pair about 3j times the length of the carapace ; their dactyli 

 are subfalcatc, that of the first pair conti'ibuting decidedly 

 less, and that of the third pair a little more, than one third 

 the total length of the appendage. The third pair of legs 



