212 "ENDEAVOUR" SCIENTIFIC RESULTS. 



Clathria c.i:lata, sp. riov. 

 (Plate xxxiii., fig. 4; and fig. 43.) 



Sponge erect, stipitale; i^'ith a tendency, wore or less- 

 •Ti'c// expressed towards a restriction of gr(nvth to one 

 plane, hut otlierwise variable in hahil. Surface charac- 

 teristically ornamented by close-set processes with deep 

 intervening sulci. Dermal membrane exceeding thin, or 

 apparetitlv absoit. Main skeleton a close reticulation of 

 well-developed horny fibres; the main fibres with loiigi- 

 ludi)udl\' atid divergingly disposed skcletid spicules, the 

 cotniecti}ig fibres vacant. I'lie echinating spicules range 

 in form, gradationally, from small straight {accessory} 

 acanthostyles to large curved smooth principal styli : 

 those of intermediate and larger size are mostly to be 

 found on the outer aspect of the superficial fibres. 

 Auxiliary spicules in moderate number occur both within 

 the fibres and scattered between. Megascleres : — (/.} 

 Smooth principal styli, 140-J20 x 10 ;< ; (;7.) entirely 

 spined acanthostyli, about jxo x 5.5 // ; (iii.) auxiliary 

 snbtylostyli, j'j^ x 5 /<. Microscleres : — 7'(>a"<j of tzvo 

 sices; the shorter, abututant, rarely exceeding go p ; the 

 longer, very rare, attaining to at least 275 p in length. 



This species — represented by six specimens — is an erect 

 stipitate sponge, somewhat variable in habit, but of very 

 characteristic external aspect owing to the extreme inequality 

 of its surface. The inequality, which is such that the surface 

 might be described as deeply sulcated or sculptured, is due to 

 the close apposition over its entire extent (including the stalk) 

 of short erect processes of variable shape but fairly uniform 

 height. The appearance of the sponge, viewed at a distance, 

 is suggestive of that of certain corals of the genus Madrepora. 



In its simplest form the sponge is probably ramose, with 

 short repeatedly divided branches disposed in one plane and 

 more or less inter-united by means of their laterally situated 

 processes. An approach to a formation of this kind is shown 

 in some parts of several of the present specimens ; but, in 

 general they are irregularly flabellate and more or less pro- 

 liferous. The largest specimen is 125 mm. in height (exclusive 

 of the stalk), 100 mm. broad, and 7 to 15 mm. thick. 



The texture is fibrous; the consistency tough, compressible,, 

 resilient. 'I'he colour (in alcohol) \aries from honey-yellow 



