106 



Front in the adult more than a third the greatest breadth of the carapace, 

 decUvous to a point near the edge, and then becoming nearly vertically deflexed ; 

 square-cut, very feebly bilobed, its surface slightly broken. The outer angle of 

 the orbit does not form a tooth, as the upper and lower borders of the orbit 

 meet almost flush there. 



Antero-lateral borders of carapace short, defined but not crest-like ; some- 

 times they form an almost unbroken curve from the orbit ; sometimes an 

 epibranchial notch or small denticle is present, this being usually the case in 

 young individuals. 



Epigastric crests low, broad, blunt, oblique, rugulose ; separated from and 

 slightly in advance of the post-orbital crests. Post-orbital crests transverse, 

 low, but fiiirly sharp, usually becoming more or less indistinct or blunt at the 

 level of the outer orbital angle. 



Length of 6th segment of male abdomen barely equal to its distal breadth 

 in the adult. 



Auteimal flagellum extremely short. 



Terminal joint of mandibular palp bilobed as described in liydrodromus 

 and callianira, etc. 



In the external maxillipeds the exopodite is longer than the ischium, and 

 is usually non-flagellate ; sometimes, however, it carries a short filamentous 

 flagellum ; the ischium is longitudinally grooved, and the merus is a good deal 

 broader than long. 



Chelipeds nearly equal in the female, very unequal in the adult male ; the 

 surface of the merus — as also in the legs — is transversely rugulose ; the carpus 

 has its exposed surface rugulose and its inner angle coarsely dentiform ; the 

 hand is, to the naked eye, practically smooth. In the larger cheliped of the 

 adult male the palm is longer than high, and is slightly shorter than the fingers ; 

 and the fingers are unevenly toothed and meet only at the tip, the curve of the 

 dactylus being very strong in old males. In these old males the length of the 

 hand and fingers considerably exceeds the breadth of the carapace. In the 

 smaller cheliped of the male, as in both chelipeds of the female, the fingers are 

 straight. 



Legs about as long as smaller cheliped ; posterior edge of propodites 

 armed with strong spines like those of the dactyli ; dactyli compressed, 

 longer than j^ropodites ; longer propodites about twice as long as broad. 

 Small tufts of bristles are present on the three terminal joints of the 

 legs. 



In the largest adults of lioth sexes the carapace is f ths inch long and 1 inch 

 broad. 



In quite young individuals the post-orbital crests are sharper, and more of 

 the form of those of callianira. 



The flagellum of the exopodite of the external maxillipeds is a variable 



