270 Carcinological Fauna of India. 



The carapace of the adult male is about 9 millim. long and 10 

 broad; that of the adult female is about 10 millim. long and 12 broad. 



In the Indian Museum collection are 3 adult males and 2 adult 

 females (one egg-laden) from off Ceylon, 34 fms. 



94. Arcania gracilipes, Bell. 



Arcania gracilipes, Bell, Ti-ans. Linn. Soc. Vol. XXI. 1855, p. 310, and Cat. Leucos. 

 Brit. Mas. p. 22 : (Haswell. P. L. S., N. S. Wales, Vol. IV. 1879, p. 58 ?) 



Carapace globular, just as broad as long, with the hepatic regions 

 dorsally sunken and flat, so as to throw the front — which does not 

 otherwise project much — into strong relief. The circumference, like 

 the dorsum of the carapace, is armed not with spines, but with numer- 

 ous large tubercles, which, like the general surface between them, are 

 closely covered with flat discoidal granules : there are altogether about 

 24 of these large tubercles. The regions of the carapace are fairly 

 well defined. The front ends in two blunt teeth : the inner canthus of 

 the orbit is not prolonged into a spine. 



The chelipeds, in the adult male, are slightly over twice the length 

 of the carapace : the arm wrist and hand are elegantly granular like 

 the carapace, the granulation in the case of the wrist and hand being 

 microscopic : the fingers are just equal in length to the hand. The true 

 legs are slender, and are microscopically granular like the hand : the 

 first pair exceed the arm by less than the length of their dactylus. 



The abdomen of the male consists of only four pieces, but the 

 second piece is hidden almost out of sight. The carapace of the adult 

 male is 7 millim. long and broad, that of the female 10 millim. 



An adult male and 5 females — three ovigerous — from the Anda- 

 mans. 



Ixa, Leach. 



Ixa, Leach, Trans. Linn. Soc. Vol. XI. 1815, p. 334. 

 Ixa, Milne Edwards, Hist. Nat. Crust. II. 131. 



Ixa Bell, Trans. Linn. Soc. Vol. XXI. 1855, p. 311, and Cat. Leucos. Brit. 

 Mus. p. 23. 



Ixa, Miers, ' Challenger' Brachynra, p. [300. 



Carapace broadly rhomboidal, produced on either side, at the junc- 

 tion of the antero-lateral and postero-lateral borders, into a great 

 sausage-shaped spine of enormous size often with an abruptly acumi- 

 nate point. The median regions of the carapace are separated on either 

 side from the branchial, either by a broad trench which bifurcates 

 anteriorly to isolate the hepatic regions from the branchial regions and 

 from the front, or by a shallow groove which has similar relations. The 



275 



