48 



spiny. The gastric and hepatic regions are well-defined : but the cardiac and 

 intestinal regions are entirely concealed by the branchial regions, which rise up 

 like a pair of mammae, and meet, but without any fusion of walls, down the 

 middle line. 



The rostrum, which is shaped exactly like the beak of a bird, is about one- 

 fourth the length of the carapace proper, measured from the pre-ocular spine, 

 and has a finely serrated edge. 



In the male the abdomen is distinctly seven-jointed ; but in the female the 

 fourth, fifth and sixth segments are immovably sutured together. 



The eyes which are small, slender, and ill-pigmented, are retractile against 

 the side of the carapace : there is a very narrow supra-orbital eave ending 

 anteriorly in a minute tooth, and there is a small post-ocular spinule. 



On the dorsal aspect the antennse are plainly visible on either side of the 

 rostrum, from the base of the 2nd joint of the peduncle : the flagella, which 

 are of hairlike tenuity, hardly surpass the tip of the rostrum. 



Owing to the prolongation of the efferent branchial canals, the front edge 

 of the buccal cavern is V-shaped, the merus of the external maxillipeds ear- 

 shaped, and the antero-external angles of the buccal cavern are pufied out 

 beyond the level of the retracted eye. 



The legs and chelipeds are slender, cylindrical, and smooth ; and are so 

 much longer in the adult male than in the adult female as to need a separate 

 description for each sex. 



In the male the chelipeds are just over twice the length of the carapace 

 and rostrum ; the first pair of legs, which are about half a dactylus length 

 longer than the second, are four and a half or nearly five times the length of 

 the carapace and rostrum, or about two and a quarter times the length of the 

 chelipeds, the third pair of legs are between two and three quarters and three 

 times the length of the carapace and rostrum, and the fourth pair are only about 

 one and two-thirds times the length of the carapace and rostrum : the fingers 

 are not quite a third the length of the palm, which is a slender cylindrical joint 

 hardly broader than the arm. 



In the female there is no such great disproportion between the legs : the 

 chelipeds are only about one and a fifth times the length of the carapace and 

 rostrum ; the first pair of legs are only about twice and a quarter, the second 

 pair only about twice, the third pair about once and two-thirds, and the fourth 

 pair about once and a quarter the length of the carapace and rostrum : the 

 fingers are not quite half the length of the palm. 



The carapace in the adult male is 42 millim. long and 42 millim. broad, in 

 the adult female 33 millim. long and 32 millim. broad. 



