120 On Indian Deep-sea Asteroidea. 



specimen). Mouth-plates very small, each being distinctly 

 formed of two fused adambulacrals, of which it carries the 

 furrow-spinelets and cross-furrow spinelets unchanged ; of the 

 two actinal spines the adoral one is remarkable in being 

 united with the corresponding spine of the fellow mouth- 

 plate in a common membranous sac, so that each pair of 

 mouth-plates appears to possess in this situation but one large 

 ligulate spine between them. 



Madreporiform plate large, salient, marginal, marked with 

 fine but deep radial striations. 



Colour in the fresh state bright cinnabar-red. 



Bay of Bengal, 561 fatlioms, grey mud. 



This species is well characterized by the small disk with 

 its bevelled edge ; by the slenderness of the rays and by their 

 short and very delicate spinature; and by the union in a 

 common investing membrane of the two large actinal spines 

 of each pair of mouth-plates. 



54. Brisinga Gunnii, sp. n. 

 Rays 14-15. 



Disk remarkably thin, its abactinal margin slightly 

 bevelled ; rays both very deciduous and very fragile, slender, 

 not inflated in the ovarian region. 



Disk covered abactinally with a very thin semitransparent 

 membrane bearing small tufts of spinelets, of which the central 

 in each tuft is sufficiently elongated to give en masse a downy 

 appearance to the disk. In one of these specimens midway 

 between the centre and the margin is a pair of large spines 

 covered with microscopic pedicellarise. 



Bays covered with a membrane of extreme delicacy, which 

 in the basal part of the ray is strengthened by from twenty 

 to thirty very contorted calcareous ridges, these standing far 

 out on each side like hoops, but becoming inconspicuous or 

 quite obsolete abactinally. In the intervals between the 

 ridges are narrow felted bands of pedicellari^, which also 

 occur in the region beyond the ridges, though, owing to 

 excessive denudation, their exact disposition is not deter- 

 minable. 



The vertebra-like adambulacral plates have the following 

 armature: — (i.) abactino-marginally a spine about six times 

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

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

 furrow-spinelet about as long as the plate ; (iv.) deep within 

 the furrow, on a distal epiphysis, a cross-furrow spine about 



