1898.] A. Alcock — Carcinological Fauna of India. 127 



Anterolateral borders very thin and sharp, obscurely divided by 

 faint notches and fainter grooves into 3 broad inconspicuous lobes, and 

 ending in a strong horizontal pyramidal lateral epibranchial spine. 



The chelipeds in the unique specimen are lost ; but the legs are 

 remarkable in having the upper edge of the merus and carpus sharply 

 carinate, the carpal joints having a second blunter and lower keel along 

 the dorsal surface. 



The le<*s and the undersurface of the body are covered with the 

 same dense extremely short pubescence as occurs in H. hextii. 



The single imperfect male in the Indian Museum comes from 

 Karachi, and is 9 millim. long and 13 millim. broad. 



Orphnoxanthus, n. gen. 



Carapace, owing to the inflation of the branchial regions almost 

 quadrilateral in outline and almost concave from side to side, but very 

 decidedly convex fore and aft, broad, the regions well defined but not 

 to any great extent areolated. 



Fronto-orbital border a little more than half the greatest breadth 

 of the carapace in extent. Front about a third the greatest width of 

 the carapace, lamellar, projecting horizontally beyond the orbits, broadly 

 and faintly bilobed. Orbital margin entire : orbits and eyes small. 



Antero-lateral border cut into four teeth ; postero-lateral borders 

 convergent only in the posterior half ; posterior border long. 



The antennules fold almost transversely. The basal antennal joint 

 is very short and only just touches the turned down edge of the front; 

 the flagellum which is very long (between 2 and 3 times the length of 

 the orbit) is lodged in the narrow orbital hiatus. 



Owing to the bulge of the outer wall of the efferent branchial canal 

 and the consequent puffing out of the pterygostomian regions, the front 

 edge of the merus of the external maxillipeds is quite transverse or 

 even slightly oblique from without inwards. 



The chelipeds are massive and unequal; the fingers are compressed 

 aud pointed. The legs are very slender. ^ 



The abdomen of the male consists of 5 segments, the 3rd-5th 

 somites being fused. 



Owing to the inflation of the pterygostomian regions the efferent 

 branchial channels are permanently open, but the low crests that define 

 them are confined to the posterior part of the endostome. 



This genus appears to represent one of the links between Galene and 

 Xantho. The single known species comes from the Bay of Bengal, 105- 

 350 fms. 



