TO INDIAN CAECINOLOGY. 371 



Genus Achelotjs, De Haan. 



99. Achelotjs granulatus (Milne-Edw.). 



A. granulatus (Milne-Edw.), A. Milne-Edwards, Nouv. Arch. Mus. Hist. Nat. t. x. p. 344 (1861). 



Gulf of Martaban, six specimens (Oates). 



The largest male is 14 mm. long and 19-5 mm. broad, while a female with ova is 

 somewhat smaller. The same silvery sheen is seen as in Neptunus argentatus, though 

 much less strongly marked in the present species. 



Distribution. From the Red Sea and E. Africa to Japan . and the Pacific (New Cale- 

 donia, Sandwich Is., Fiji Is.). 



100. Achelotjs Whitei, A. Milne-Edw. 



A. Whitei, A. Milne-Edwards, Nouv. Areh. Mus. Hist. Nat. t. x. p. 313, pi. xxxi. fig. 6 (1861). 



( =? Neptunus gracilimanus, Stm.). 



Gulf of Martaban, seven specimens (Oates). Common at Madras (J. B. R.). 



This species may be recognized at once by its remarkable chelipedes, the merus of 

 which is long and very broad, while the more distal joints, and especially the fingers, are 

 extremely slender; the fingers also are acute and slightly upturned. Neptunus gracili- 

 manus, Stimpson, is probably identical with A. Whitei ; the description of the former 

 agrees with that of the present species, and the posterior lateral spine is distinctly longer 

 than those in front of it, especially in young individuals, which gives the species almost 

 the appearance of a Neptunus. Indeed, it shows that Neptunus and Achelous can scarcely 

 be separated, though it is perhaps convenient to retain the latter term for those forms 

 in which the lateral spines are greatly reduced. 



The largest specimen (a female) is 19 mm. long and 30 mm. broad, not including the 

 lateral spines ; the merus of the left chelipede is 17'5 mm. long and 8 mm. broad ; the 

 carpus and propodus 30 mm. long, and the greatest breadth or height of the hand 4 mm. 



Distribution. Borneo (A. Milne-Edwards); south of New Guinea (Iliers). 



101. Achelotjs orbicularis, Richters. 



A. orbicularis, Richters, Beitrage zur Meeresfauna der Insel Mauritius uud der Seychellen, p. 153, 

 Taf. xvi. figs. 14, 15 (1880). 



Gulf of Martaban, two males (Oates). 



The carapace is narrow, smooth, and depressed, with the nine antero-lateral teeth 

 subequal in size, or even diminishing slightly on passing backwards ; the postero-lateral 

 margin is almost straight and without any concavity. The front is six-tootbed, and the 

 median teeth minute. The merus of the chelipedes is enlarged, angulated externally, 

 and with two spines on the posterior margin. 



In the larger specimen the carapace is 8 - 5 mm. long and 10 - 5 mm. broad ; the distance 

 between the external orbital angles is 7"6 mm. 



Distribution. Seychelles (Richters). 



