220 



Memoirs of the Indian Museum. 



[Voi,. V, 



1 ' Under the catamarans on the shore a Doryline ant had constructed galleries in 

 the wet sand. These galleries in several cases were noticed to lead to the burrow 

 of a megalopa or newly perfected crab. In such cases the ants were devouring, or 

 had already devoured, the rightful owner, but whether they had waited till its death 

 before doing so, or had attacked it and eaten it alive, could not be ascertained." 



fc Full-grown crabs of this species are much more retiring in their habits than 

 young and half-grown individuals, which, at any rate in dull weather, may be. seen 

 running about the shore, and even in the neighbouring Casuarina woods at all times 

 of the day. The pellets of sand produced in excavating the burrows were merely 

 shovelled out of the holes in a fan-shaped mass and no effort seemed to be made, at 

 any stage in the life-history, to arrange them neatly. In this respect the holes 

 offered a striking contrast to those of Dotilla intermedia on the same beach." 



The megalopa and first post-larval stage are figured in text figs. 6a and 6b from 

 material obtained by Dr. Annandale at Ennur. The megalopa is remarkable for the 



a, b. 



Fig. 6. — Ocypoda macrocera, Milne-Edwards. 

 a. Last megalopa stage. b. First post-larval stage. 



presence of deep cavities at the postero-lateral angles of the carapace, into which 

 the last pair of the legs can be folded. 



Ocypoda macrocera is common on the sandy shores which fringe the outer chan- 

 nel of the Chilka L,ake and also occurs on the adjacent islands. It extends from the 

 mouth of the lake up to Satpara and is found throughout the year, both when the 

 water in the channel is fresh and when it is salt. We failed to find specimens on the 

 neighbouring shores of the Bay of Bengal ; but I have little doubt that it occurs 

 there. In the largest specimen obtained, a female, the breadth of the carapace is 

 32 mm. 



The species is known only from the Bay of Bengal and the Gulf of Siam. 



Ocypoda platytarsis, H. Milne-Edwards. 



1900. Ocypoda platytarsis, Alcock, Journ. Asiat. Soc. Bengal, LXIX, p. 348. 

 This species is abundant on the sandy banks of the outer channel near the- mouth 

 of the lake. Like 0. macrocera it is found at all seasons of the year, when the water 



