the * Challenger ' Monaxonida. 487 



by -013 millim., in the fibres; (2) similar, but much smaller, 

 length about "4 millim., in the surface-brushes. 

 Locality. Off the S.W. coast of Patagonia. 



Suberites ramulosa, n. sp. 



Stipitate. Stem long, slender, simple or branched, ending 

 below in spreading rootlets, and each branch expanding above 

 into a pear-shaped head. Texture rather soft and spongy. 

 Surface hispid. Oscula, one at the summit of each head. 

 Skeleton, a dense spicular axis in the stem, and in the head 

 longitudinal tracts of similar spicu les with loose brushes of 

 smaller ones at the surface. Spicules : — (1) straight, st^Ait, 

 fusiform spinulates, usually blunt, and with well-marked sub- 

 globular heads, size ] "8 by '063 millim. ; (2) slenderer, 

 usually sharp-pointed spinulates, size I'O by "028 millim., but 

 variable, in the surface-brushes. 



Localities. Station 207, Philippine Islands, TOOfath.; Station 

 209, Philippine Islands, 95 fath. (var. ct/lindrifera, with large 

 blunted acuates in place of the large spinulates) . 



Genus Polymastia (Bowerbank). 



Massive, sessile, corticate ; differing from Suherites in the 

 presence of mammiform processes on the upper surface. 

 Skeleton-spicules spinulate or acuate. No long supporting 

 fringe of spicula as in Tnchostemma. 



Polymastia corticata^ n. sp. 



Cushion-shaped ; cortex 2| millim. thick. Milky white. 

 Very minutely hispid. Mammiform processes of two kinds : — 



(1) very numerous, hollow, flattened, closed, height ^ inch, 

 breadth § inch ; (2) a very few flattened conical tubes, some- 

 times fairly widely open at summit, height 1 inch, breadth at 

 base ^ inch ; these are the oscular tubes. Skeleton : — (a) Of 

 body : (1) on the outside a dense layer of brushes of small 

 spinulates, "28 millim. thick ; (2) below this a much thicker 

 layer of. vertically set large acuates or subspinulates ; below 

 this " cortical " layer the skeleton is confused, with loose 

 fibres, {b) Of the mammiform processes, outermost cortical 

 layer as before, then stout longitudinal fibres of large spicules 

 and a loose network of the same. Spicules : — (1) sharp, 

 fusiform spinulates with oval heads, size "28 by *008 millim. ; 



(2) fusiform acuates or subspinulates, sharp-pointed, size "98 

 by '022 millim. 



Locality. Station 125, between Pernambuco and Bahia, 

 1200 fath. 



33* 



