REPORT ON THE MONAXONIDA. 205 



axis of longitudinally placed spicules, from which radiate bands of very loose spiculo-fibre 

 to the surface, like the spokes of a wheel ; these project more or less beyond the surface 

 and give rise to its hispidity. (b) The skeleton of the head ; this is very diffuse, and 

 consists of loose bands of sjjiculo-fibre which run more or less vertically upwards towards 

 the top of the sponge, radiating very slightly ; as they approach the surface they break 

 up into brushes of smaller tylostylote spicules. Owdng to the direction in which they 

 run it is only at the top of the sponge that the skeleton fibres abut vertically against 

 the surface ; lower down their direction lies more or less parallel with it, and they only 

 run very obliquely into it. 



Spicules. — Megasclera; of one kind only, viz., smooth tylostyli (PL XLV. figs. 4, 

 4o, 46, 4c), with straight, or very slightly curved shafts and fairly well-developed, hemi- 

 spherical or subglobular heads ; tapering gradually to a fine point at the apex. Size 

 extremely variable, in the deeper fibres very long and stout, towards the surface usually 

 much smaller. They may attain a length of about 2'0 mm. and a diameter of about 

 0'03 mm.; but, as already stated, they are very much smaller in the radiating brushes at 

 the surface of the sponge, commonly measuring about 0"4 or 0"5 by about O'Ol mm. 



The most remarkable features of this sponge are its great softness and looseness of 

 texture, as compared with the more typical species of Suberites, and the reduction of the 

 " dermal crust" of spicules, which no longer forms a distinct cortical layer. 



Locality. — Station 148, January 3, 1874; south of the Crozets ; liottom, hard 

 ground, gravel, shells ; depth, 240 to 550 fathoms. One specimen. 



Suberites elongatus, Ridley and Dendy (PI. XLIII. figs. 11, 12). 



1886. Suberites elongata, Ridley and Dendy, Ann. and. Mag. Nat. Hist., ser. 5, vol xviii. p. 486. 



Sponge (PI. XLIII. figs. 11, 12) consisting of a slender, fleshy-looking stalk, expanding 

 below into attaching rootlets ; and an oval, more or less elongated head. The relation, 

 as regards size, between the head and the stalk is a very variable one ; in one specimen 

 the head is about 12 mm. and the stalk about 44 mm. long, while in a second the 

 head is 25 mm. and the stalk only about 12 mm. long. The respective diameters of 

 the head and stalk are, on the contrary, pretty constant, that of the head being about 

 4 mm. and of the stalk 1 mm. Colour in spirit pale yellow. Texture firm, cork-like. 

 Surface even, on the head minutely hispid, on the stalk stiU more minutely so. Oscula 

 very few, minute, scattered, sometimes one or two, sometimes none, discernible ; usually 

 at or near the top of the head. 



Skeleton. — The dense central axis of the stem, composed of longitudinally placed, 

 stylote spicules, is continued into the head as a not very definite central core, from which 

 radiate, outwards and upwards, bands of spiculo-fibre to the surface of the sponge ; on 

 approaching the surface these branch more or less and the points of their terminal spicules 



