1900.] 



A. Alcock — Carcinoloqical Fauna of India. 



389 



Legs long and slender, with long dactyli furnished with hook-like 

 teeth at the end of the posterior border : the 2nd pair of legs are nearly 

 three times the length of the carapace. 



A single male from Port Canuiug near Calcutta : its carapace is 

 8"5 millim. long and 6 million, in its greatest breadth. 



Family GRAPSID^E Dana. 



Key to the Indian Genera. 



I. The antennnles fold beneath the front in the ordinary 

 way:— 



1. No oblique hairy ridge on the exposed surface of 

 the external maxillipeds : — 



i. A very wide gap between the external maxil- 

 lipeds, the exopodites of which appendages 

 are narrow, and the palp of which appendages 

 articulates at or near the antero-external 

 angle of the tneras : the abdomen of the 

 male fills all the space between the last pair 

 of ambulatory legs (Grapsinas) : — 



A. Front less than half the greatest 

 breadth of the carapace : merns of 

 the external maxillipeds longer than 

 broad : — 



a. Fingers with broad spooned tips : 

 flagellum of exopodite of exter- 

 nal maxillipeds well developed. Grapsus. 



b. Fingers acnte, not spooned : 

 flagellum of exopodite of exter- 

 nal maxillipeds absent Geograpsus. 



B. Front more than half the greatest 

 breadth of the carapace : merus of the 

 external maxillipeds broader than 

 long:— 



a. Antennas completely excluded 



from the orbit Metopograpsus. 



b. Antennas in the orbital hiatus... Pachygrapsus. 

 ii. A moderate gap between the external maxil- 

 lipeds, the exopodites of which appendages 



are broad, and the palp of which appendages 

 articulates near the middle of the anterior 

 border of the broad merus : the abdomen of 

 the male does not quite fill all the space 

 between the last pair of legs (Vanminx) : — 

 A. Exognath of the external maxillipeds 

 not aa broad as the ischiognath : ter- 

 minal joints of legs thin broad and 

 compressed Varuna. 



