514 " THETIS " SCIENTIFIC RESULTS. 



The outer surface presents a series of low longitudinal ridges 

 which are more or less radiate and terminate at the ends of the 

 lobes ; the inner aspect exhiWits numerous shallow radiating 

 grooves, which are furnished with abundant oscula (?) pores from 

 0*5 to 1 mm. or more in diameter ; when viewed by transmitted 

 light the sponge appears as if it had been perforated with very 

 small shot. The dermis is somewhat silvery white, minutely 

 porous, and fairly smooth. Texture elastic and rather tough ; 

 colour yellowish-grey or cream. 



Skeleton plumose consisting of loosely arranged whispy -bundles 

 of spicules ; the fibi^es when distinct are generally about 0'5 mm. 

 in diameter, the same distance apart, and enclosed in a consider- 

 able amount of pale diffused spongin. The dermal layer is about 

 O'l in thickness, and is charged with numerous small oxea. 



Megascleres : — styli of various shapes and sizes. 



(1) Tapering, acutely pointed styli, with a sharp bend near the 

 base, or curved in the basal third ; size 0"6 to 0"15 b}'^ 0'G2 to 

 0"03 mm.; these are very plentiful. 



(2) Straight, acutely pointed styli ; size 0'5 by 0-02 to 0'03 

 mm. 



(3) Long, cylindrical, sharp point styli ; size 1*3 to 1'5 by 0*02 

 mm. 



Microscleres : — small, straight oxea; size 0'08 to 0"004 mm. 

 Besides the above no other oxea have been observed. 



RASPAILIA, Nardo. 



RASPAILIA ECHINATA, s^p. nov, 



(Plate xlvi., fig. 37.) 



Stations 44-47. 



Sponge pedunculate, with a small attachment disc, a well- 

 defined pedicel, and numerous dichotomous branches which are 

 cylindrical and disposed in a plane. The apices of the branches 

 are neatly rounded except in two cases — indicating further dicho- 

 tomization — in which they are broad and compressed ; their 

 diameter is about 5 to 7 mm. Surface minutely honeycombed ; 

 the cells are generally oblong, and their marginal walls are fur- 

 nished with numerous rigid, sharp, aculeations from 1 to l"5mm. 

 in height and about 0-5 to 1 mm. in diameter. Texture hard, 

 elastic, and extremely harsh to the touch ; colour dark greyish- 

 brown. 



Skeleton consisting of a series of slender subparallel fibres 

 without much evident spongin ; their course is axial, and at the 

 surface they bifurcate and terminate in closely arranged tufts of 

 long, stout styli. The primary fibres are about 1*5 mm. in dia- 



