Indian Dee-p-sea Asteroidea. 119 



furrow spine separating the pairs of tube-feet. All these 

 spines are hyaline, fluted, and invested in sacs formed of 

 membrane and felted microscopic pedicellarige. 



Actinostome large (25 millira. in diameter in the type 

 specimen). Mouth-plates small, each plate formed of two 

 adambulacrals, with the furrow and cross-furrow spinelets 

 unchanged and the actinal spines not much modified; the 

 most adoral actinal spine is enlarged and is often united with 

 its fellow of the same pair in a common membranous 

 investment. 



Madreporiform plate rather small, excavated centrally, with 

 fine radial striations, marginal in position. 



Colour in the fresh state bright cinnabar-red. 



Andaman Sea, 405 fathoms, green mud. 



This species stands intermediate between B. insularum 

 and the next species, B. hengalensis ; it is well characterized 

 by the extensive development along the rays of feeble calca- 

 reous plates. 



53. Brisinga bengalensisj Alcock and Wood-Mason. 

 Brisinga bengalensis, Aun. & Mag. Nat. Hist., Dec. 1891, p. 439. 

 Rays 14. R = 25 r. 



Disk small (its diameter being 30 millim. in the type 

 specimen), depressed centrally, with a strongly bevelled 

 abactinal margin ; rays very deciduous, but not otherwise 

 very fragile, long, slender, hardly inflated in the ovarian 

 region. 



Abactinal surface of the disk much as in B. andamanica ; 

 abactinal surface of the rays covered with a very delicate 

 transparent membrane, which in the basal ninth of the ray is 

 strengthened by about twenty close cross bands or half-bands 

 of spiny plates that are not very much more salient tiian the 

 cross bands of felted pedicellarige that occur throughout the 

 ray. 



The vertebra-like adambulacral plates have the following 

 armature : — (i.) abactino-niarginally a spine about five or six 

 times as long as the plate ; (ii.) actino-marginally a spine 

 twice to two and a half times as long as the plate ; (iii.) two 

 furrow-spinelets not quite half as long as the plate ; (iv.) 

 deep within the furrow, on a distal epiphysis, a cross-furrow 

 spine not quite as long as the plate, separating the tube-feet. 

 All these are hyaline, fluted, and clothed with membrane and 

 felted pedicellariai. 



Actinostome very large (21 millim. in diameter in the type 



