Carcinological Fauna of India. 267 



only one wanting being that between the gastric and cardiac regions. 

 The margins of the carapace are armed with eleven spines of moderate 

 size, situated as follows : — one, pointing obliquely forwards, in either 

 antero-lateral border, at the culmination of the sub-hepatic region; one 

 on either side just behind the groove that separates the hepatic from 

 the branchial region ; one, claw-like, at either (median) lateral epibran- 

 chial angle ; one, pointing obliquely backwards, just abaft the middle 

 of either postero-lateral border ; one at either end of the posterior bor- 

 der ; and one, pointing straight backwards, in the middle of the intesti- 

 nal region. The front ends in two sharp-cut laminar teeth. 



The slender chelipeds, in the adult male, are just over twice the 

 length of the carapace (spine excluded) ; the arm is usually, but not 

 always, covered in all or the greater part of its extent with miliary 

 granules similar to those on the carapace ; the almost filiform fingers are 

 as long as the hand and rather more than half the wrist combined. The 

 true legs are slender and smooth ; their dactyli are scantily fringed with 

 hair in their distal half : the first pair exceed the arm in length by 

 their last two joints. 



The length of the carapace of the adult male is about 16 millim., 

 and the breadth about 14 millim. ; of an adult female the dimensions 

 are 18 millim. by 16 millim. 



In the Indian Museum collection are young and adults of both 

 sexes, from the Andamans and from the Madras side of Palk Straits. 



90. Arcania novemspinosa, Adams & White. 



Iphis novemspinosa, Adams & White, ' Samarang ' Crust, p. 56, pi. xiii. fig. 1. 



Arcania novemspinosa, Bell, Trans Linn. Soc, Vol. XX I. 1855, p. 309, and Cat. 

 Leucos. Brit. Mus. p. 21 : Haswell, P. L. S., N. S. Wales, IV. 1879, p. 58, and Cat. 

 Austral. Crust, p. 131 : de Man, Archiv fur Naturges. LIII. 1887, i. 392. 



Differs from A. undecimspinosa, De Haan, only in the following 

 characters : — 



1. The surface of the carapace, in the adult, is almost smooth — 

 at any rate is without isolated miliary granules or prickles. 



2. The marginal spines are very much larger, with the single 

 exception of the spine on either side situated at the junction of the 

 sub-hepatic and branchial regions, which is a mere denticle or granule. 



3. With the exception of a faint groove between the hepatic and 

 branchial regions, and of a still more indistinct break of level between 

 the branchial and intestinal regions on either side, the regions of the 

 carapace are not defined. 



4. The front is more prominent. 



5. The chelipeds in the adult male are 2| times the length of 

 the carapace, and the arm is only very finely granular, and at the base only. 



272 



