188 CEYLON PEARL OYSTER REPORT. 



tracted below, but attached by a broad base. Surface even, but granular or minutely 

 conulose, the conuli being in part covered over by a translucent dermal membrane ; 

 very minutely hispid. Vents small, few, scattered ; surrounded by feebly developed 

 grooves arranged in a somewhat stellate fashion. Colour (in spirit) pale yellowish- 

 grey. Texture compact, very hard ; surface harsh to the touch ; internal structure 

 radially columnar. Greatest diameter about 23 millims. 



The skeleton is composed chiefly of close-set, rather irregular, plumose columns of 

 megascleres, running at right angles to the surface and ending in the small conuli or 

 granules. These columns are connected by numerous spicules, isolated or in loose 

 bands, which run across at right angles from one to another, while numerous 

 megascleres are also scattered irregularly in the soft tissues. 



Spicules. (1.) Oxea (Plate XII., fig. 5, b) ; short, fairly stout, fusiform, gently and 

 symmetrically curved, gradually sharp-pointed at each end ; size up to about 

 0*39 millim. by - 024 millim., but usually somewhat less, especially in diameter. 



(2.) Styli (Plate XII. , fig. 5, a) ; with broadly rounded base and gradually sharp- 

 pointed apex ; usually more or less curved towards the base ; dimensions about the 

 same as those of the oxea. Perhaps not quite so abundant as the oxea. 



(3.) Trichodragmata (Plate XII., fig. 5, c, d) ; short, stout bundles of very slender, 

 hair-like spicules, the whole bundle having, as usual, a faint brownish colour ; 

 dimensions of the entire bundle about 0'02 millim. by 0'008 millim. ; abundant 

 towards the surface of the sponge. 



This curious little sponge is evidently closely related to Topsent's Thrinaeophora 

 spissa (48) from the North Atlantic, and forms an interesting connecting link between 

 that species (which has only oxeote megascleres, apparently arranged in a hali- 

 chondrioid rather than an axinellid fashion) and the more typical species of the 

 genus. 



K.N. 355 (Ceylon seas). 



Axinella, Schmidt. 



Axinellidse of varying habit, but not flabellate. With plumose skeleton composed of 

 smooth styli or oxea and no microscleres. 



Axinella labyrinthica, Dendy. 



There are three specimens of this sponge in. the collection. The species is easily 

 recognisable by its external appearance, and I have nothing to add to my former 

 description, Dendy (3), 1889. 



R.N. 33, 103 (both from Gulf of Manaar) ; 357 (Ceylon seas). 



Axinella manus, n. sp. Plate XII. , fig. 8. 



Sponge erect, stipitate, branched in a somewhat palmate manner, but with the 

 branches coming off at different levels and curving slightly towards one another (so 

 as to suggest a hand holding a ball). Stem cylindrical, slightly expanded below, 



