Catahxj up of Non-Calcareous Sponges. 241 



spicules. These horny fibres form a close reticulation in the 

 axial portion of the sponge and to a less extent towards the 

 periphery. The relation of the spicules to the spongin is not 

 very definite, they are chiefly embedded in and projecting from 

 the main fibres. 



Megasderes slender, ranging from stylote to oxeote, often with 

 irregular ends. Size very variable, up to about 0-3 by - 006 

 mm. 



Microsderes, (a) very slender, simple and contort sigmata, 

 varying in size, up to about 033 mm. from bend to bend. Very 

 abundant, in bundles (sigmadragmata) or scattered separately ; 

 (/>) short, hair-like raphides, mostly in dense bundles (trichodrag- 

 mata), about O025 mm. long. Very abundant. 



This is one of the best characterised and altogether most 

 satisfactory species in the collection. 



R.N. 352 (19 f.; "brownish-red"); 388; 616 (x, 19 f.; 

 "orange-rufous, lighter orange below"); 654 (x, 20 f.; "orange- 

 rufous"); 812, 1063. 



Sigmaxinella flabellata, Carter, sp. 



Axinella flabellata, Carter, A.M.N.H., November, 1885, p. 361. 



Sponge composed of proliferous lamella? about a quarter of an 

 inch thick, springing from a short, thick stalk. Surface coarsely 

 granular or minutely conulose. Vents minute, marginal or 

 scattered. Colour in spirit pale greyish-yellow. Texture tough, 

 fibrous, resilient. 



Skeleton, dense, composed of loose, plumose, spicular fibres, 

 curving outwards towards the surface, beyond which the ends of 

 the terminal spicules project slightly. 



Megasderes, more or less curved styli, evenly rounded at the 

 base and gradually and sharply pointed at the apex ; commonly 

 rather stout, up to about 0*29 by - 0166 mm., but varying, 

 especially in thickness. 



Microsderes, (a) numerous, very slender, simple and contort 

 sigmata, measuring about - 0166 mm. from bend to bend ; (b) 

 trichodragmata and scattered rhaphides, up to about 0*049 mm. 

 long. 



Three of the specimens are beset with parasitic Actinozoa. 



10 



