44 



Our numerous specimens, which represent both sexes at various ages come 

 from numerous stations in the Andaman Sea and from depths varying from 

 112 to 250 fathoms. 



The latest additions are two adult males and an adult female from 185 fms., 

 dredged by Dr. A. R. Anderson, from which an amended diagnosis of the genus 

 has been drawn up. 



EcMnox)lax riibida, Alcock. 



EchinofUx ruUda, Alcock, J. A. S. B., Vol. LXIV. pt. 2, 1895, p. 179 : III. Zool. Investigator, Crnst. pi. xrii, 

 figs. 2, 2a. 



Differs from the preceding species in the following characters, specimens of 

 the same sex and of approximately the same size being compared :— 



(1.) The branchial regions are not inflated above the level of the cardiac 

 region, and the latter region is therefore larger and better defined : 



(2.) The carapace, instead of being everywhere covered with pungent 

 acicular spines of uniform size, is finely granular, with certain definitely placed 

 distant thornlike spines of conspicuous magnitude, namely :— four in triangle on 

 the gastric region, two side by side on the cardiac region, two side by side on 

 the intestinal region, three on each hepatic region, and three on each epibranchial 

 region : besides these there are some smaller spines on the lateral aspect of the 

 pterygostomian and branchial regions, and a very large spine at either antero- 

 external angle of the buccal cavern : 



(3.) The rostral spines are less divergent, and have elegantly curved tips : 



(4.) The abdominal terga (of the female), instead of being everywhere 

 closely covered with pungent spines, are merely finely and distantly granular, \x\t\\ 

 a single large spine on the first tergum, and a pair of smaller spines on the 

 second, in the middle line : 



(5.) The legs are much less spiny, the propodites of the ambulatory legs 

 being fringed with stiff bristles instead of spines : 



(6.) The colour differs, being, in spirit specimens, a warm brown, instead 

 of a pale yellow. 



A single female specimen, apparently (from the condition of the brood- 

 pouch and the form of the alxlomen) an adult, from the Andaman Sea, 90 to 

 177 fms. 



The length of the carapace is 35 millim., its breadth 21 millim, 



Cyt'tOindia, Miers. 



Cyrtomaia, Miers, Challenger Brachynra, p. 1-1 : Mary J. Rathbun, Proc. U. S. Nat. Mua, XVI. 1893 (1891), 

 p. 228 : Alcock, J. A. S. li. Vol. LXIV. pt. 2, 1895, p. 16.3. 



Very closely related to Echinoplax, from which it appears to differ only in 

 the following respect : — 



