488 Messrs. S. 0. Ridley and A. Dendy on 



Polymastia agglutinans^ n. sp. 



Sessile, subglobular, incrusting and enveloping pebbles 

 &c., and cementing on to its own surface numerous small 

 foreign objects. Giving off long, stiff, slender, cylindrical, 

 hollow processes closed at tlie top, free from foreign objects. 

 Diameter of body about | inch, length of fistula up to \ inch. 

 Skeleton: — (a) Of body: a dermal layer of dense brushes of 

 small spicules only present between the foreign bodies, which 

 replace it ; beneath this scattered spicules and stout columns 

 of spiculo-fibre running to the surface, {h) Of processes : out- 

 side is a dense crust of small projecting spinulates, then a 

 reticulation of larger spicules parallel with the surface, backed 

 by a circle of stout longitudinal bands of spiculo-fibre. 

 Spicules: — (1) straight acuates or subspinulates, subfusiform, 

 size up to 1*17 by •0157 millim. ; (2) very small slender 

 spinulates, size '175 by "004 millim. (chiefly dermal). 



Locality. Station 75, off the Azores, 450 fath. 



Genus Proteleia * (Dendy & Ridley). 



Differs from Polymastia in the presence of a grapnel-like 

 spicule projecting from the surface of the body. 



[Protdeia Sollasi, Dendy & Ridley. 

 Locality. Simon's Bay, Cape of Good Hope, 10-20 fath.] 



Genus Trichostemma (M. Sars"!. 



Corticate, free-living, discoidal or hemispherical, with a 

 marginal fringe of long supporting spicula. Skeleton-spicules 

 mainly spinulate. 



Trichostemma Sarsii^ n. sp. 



Discoidal ; flattened, especially on tlie upper surface. Dia- 

 meter of largest specimen ^ inch, thickness g inch. One osculum 

 (or more ?) on the summit of oscular tube (or tubes ?) on the 

 flat surface. Skeleton : a dense thatch of spicules covers the 

 lower convex surface, radiating outwards and upwards ; the 

 upper surface is provided with a thick cortex of projecting spi- 

 cules, beneath this lies a confused mass of spicules. Spicules : — 

 (1) straight, slender spinulates or subspinulates, forming the 

 thatch and fringe, length up to 4*7 millim., diameter '02 

 millim. ; (2) short, stout, fusiform spinulates, in the interior 



* For full description and discussion of genus and species vide Ann. 

 & Map. Nat. Hist. ber. 5, vol. xviii. p. 152, pi. v. 



