286 A. Alcock — Oarcinological Fauna of India. [No. 2, 



Bay of Bengal 1300 fathoms, Laccadive Sea 1200 fms. 

 This species may possibly be only a variety of Ethusa (Ethusina) 

 gracilipes, Miers, Challenger Brachyura, p. 382, pi. xxix. fig. 1. 



106. Ethusa (Ethusina) desciscens, n. sp. 



Only differs from E. investigatoris (1) in its smaller size, (2) in 

 having the eyestalks somewhat more mobile, and (3 ) in having the hand 

 of one cheliped (in the male) much larger than the other. 



I shonld have regarded it as a variety of E. investigatoris but that 

 two specimens coming from very different localities and depths present 

 the same peculiarities. 



Length of carapace of largest specimen 9 millim., extreme breadth 

 8 millim. 



Andaman Sea 265 fathoms, Laccadive Sea 912 to 931 fms. 



Cymonomops, Alcock. 



Cymonomops, Alcock, Ann. Mag. Nat. Hist., May 1894, p. 406. 

 Allied to Gyclodorippe, Cymonomus, etc. 



Carapace of th.e Dorippe type (that is to say having its greatest 

 breadth at its extreme posterior limit and leaving about half of the 

 abdominal terga exposed to dorsal view), but arched anteriorly almost in 

 a semicircle ; its regions well defined in much the same way as Dorippe. 

 The front is narrow and the whole fronto-orbital region lies well inside 

 the semicircular cnrve of the antero-lateral margins : the narrow front 

 ends in two little teeth between and beyond which can be seen the roof 

 of the greatly prolonged buccal cavern, as in Dorippe polita. On either 

 side of the front is a spine that forms the roof of the orbit, and outside 

 of this spine, and separated from it by a deep notch, is a spine that 

 forms the outer wall of the orbit. 



The eyestalks are slender, moderately long, and freely movable : 

 the eyes are almost without pigment. 



The antennules have their basal joint lodged in a deep crevice 

 between the edge of the anterior prolongation of the buccal cavern and 

 the antennae : their long flagellum cannot be concealed in flexion. The 

 antennae are large, but are much smaller than the antennules. 



The buccal cavern is of great size, — not much less than half the 

 length of the body, and is gradually narrowed anteriorly, and prolonged 

 beyond the tip of the front : it is closed, except at its extreme frontal 

 tip, by the long narrow external maxillipeds, the merus of which is not 

 very much shorter than the ischium measured along the inner border 

 and the flagellum of which is expossed in flexion : the long narrow 

 pointed exognath is not much longer than the ischium : beneath the 



