104 A. Alcock — Garcinological Fauna of India. [No. I, 



Nautilocorystes, Edw. 



NauHlocorystes, Milne Edwards, Hist. Nat. Crust. IT. 149. 

 Dicera, De Haan, Faun. Japon. Crust, p. 14. 



Carapace eloagfate-obovate, slightly convex from side to side, 

 smooth without distinction of regions, the antero-lateral borders longer 

 than the postero-lateral and armed with five teeth. 



Front moderately broad, horizontal, moderately prominent, cat into 

 2 or 3 teeth. 



The antenuules fold longitudinally. Antennae coarse, setaceous, 

 the basal joint occupying the orbital hiatus, the flagellum about half as 

 long as the carapace. 



Buccal orifice elongate subquadrate, not defined anteriorly : exter- 

 nal maxillipeds elongate, the merus narrower than the ischium and 

 bearing the flagellum at its summit. Even in repose the external 

 maxillipeds partly conceal the antennules. 



Chelipeds short, much more massive than tlie legs. 



Legs compressed, the first 3 pair end in a lanceolate dactylus the 

 last pair end in a blade-like swimming dactylus. 



1. Nautilocorystes investigatoris, n. sp. 



Carapace elongafce-obovate covered with a multitude of fine brown 

 longitudinal lines, smooth. 



Front about a third the greatest breadth of the carapace, slightly 

 prominent beyond the orbits, cut into 3 teeth. 



Antero-lateral borders cut into 5 irregularly disposed teeth includ- 

 ing the outer orbital angle. 



Inner angle of lower border of orbit acutely dentiform, prominent 

 beyond the level of the front. 



Chelipeds equal, about as long as the carapace : a spine at the 

 inner angle of the wrist and two spines on the upper surface of the 

 hand — one being in front of the apex of the wrist-joint the other behind 

 the finger- joint. 



Legs compressed, much slenderer but not much shorter than the 

 chelipeds, hairy : the dactylus of the last pair is broadly blade-shaped 

 as in N. ocellatus. 



In the Indian Museum are 2 females — one with eggs — from the 

 Vizagapatam coast 15-17 fms. The carapace is 6 25 millim. long and 

 5*5 millim. broad. 



This species differs from N. ocellatus in the following particulars : — 

 the front is 3-spined, the inner suborbital angle is extremely prominent 

 and spiniform, tJiere are two spines on the hand, and the colour- 

 markings are fine longitudinal lines. 



