1900.]. A. Alcock — Carcinological Fauna of India. 365 



58. Dotilla ajjinis, n. sp. 



Differs from D. sulcata, with specimens of which, from the Red 

 Sea, I have compared it, only in the following characters : — 



(1) there is no spine on the under surface of the .arm, (2) the 

 fingers are not so long as the palm, (3) there is a small tympanum on 

 the dorsal surface of the moras of the last pair of legs, whereas in 

 D. sulcata only the tympanum on the ventral surface is present. 



The carapace behind the gastric and inside the branchial regions, 

 forms a smooth semicircular facet, but all its anterior and lateral 

 regions have a curiously convoluted sculpture, the convexities of the 

 convolutions being finely granular. 



The grooves that define these convolutions form, when viewed as a 

 whole, a sort of five-rayed star, the anterior ray (which runs up 

 between the eyes on to the front) being the shortest, the antero-lateral 

 rays (which run towards the outer angles of the orbit) being a little 

 longer, and the postero-lateral rays (which really are triple) being the 

 longest of all. 



The pterygostomian regions and neighbouring part of the side- 

 walls of the carapace, and the meropodites of the external maxillipeds 

 have the same curious convoluted sculpture. The orbits are shallow 

 but are perfectly defined. 



The merus of the external maxillipeds is more than twice the size 

 of the ischium. 



Chelipeds (measured round their curve) not twice the length of 

 the carapace : no spine on any of their segments : fingers not so long as 

 the palm. 



Legs slightly longer than the chelipeds, their meropodites not at 

 all broadened but all having a " tympanum " : except in the case of the 

 last pair of legs — in which the dactylus is remarkably long — the dactyli 

 are rather shorter than the propodites, 



"No tympana on the sternum. 



In the Indian Museum are 4 specimens from Aden and the 

 Baluchistan coast. The carapace of the largest is 53 millim. long and 

 7*3 millim. broad. 



59. Dotilla intermedia, de Man. 



Dotilla intermedia, de Man, Journ. Linn. Soc, Zool., XXII. 1887-88, p. 135, 

 pi. is. figs. 4-6 (1888;. 



Carapace sculptured in much the same way as in D. affinis, only 

 the grooves are not so deep and distinct, and there is an additional 

 groove running parallel with the posterior margin. 



