Sponges from the Atlantic Ocean. 321 



alluded to by Wy. Thomson ('Depths of the Sea,' p. 113), 

 may not be the same as his C. pennatula ; but I cannot see 

 among these specimens (all of which are now before me) any 

 that are not mere modifications inform only of Sars's C. ahys- 

 sicola, viz. a main stem with pinnate branches corticated with 

 the drooping filaments or branchlets. 



The '* peculiar form in jar 65 " above described is in no way 

 like Sars's C. abyssicola, while C. corticocancellata is the 

 "fourth" species of this kind of sponge to which I have alluded, 

 but have omitted to mention further (' Ann.' 1874, vol. xiv. 

 p. 218), wherein the anchorate possesses such a peculiar shape 

 in the arrangement and number of the divisions of its head- 

 like extremities. These, however, in Halichondria ahyssi^ 

 which I thought were lateral, have now been found, as I 

 have before stated, by Mr. Higgin to be circular, so that the 

 minute spicules of which they are part are therefore as birotu- 

 late as the birotulate spicules of liyalonema &c., but divided 

 also, as before stated, into twelve arms in the way already 

 mentioned under Halichondria abyssi. 



Hymeraphia verticiUata, Bk. (PI. XIV. fig. 21 &c,, 

 and PI. XV. fig. 39, a, h.) 



General form thin, laminiform, incrusting, covered irre- 

 gularly with aculeations of different heights, here and there 

 presenting a short tubular prolongation. Colour cream-yellow 

 or dark grey. Surface uniformly aculeated, each aculeation 

 prolonged by the projection of a large spicule from its summit, 

 surrounded by a number of smaller spicules, while the aculea- 

 tion itself or sponge portion is chiefly composed of the dermal 

 layer, which is densely charged with its spiniferous spicules ; 

 dermis thick, membranous, textile-like. Pores in minute 

 depressions between the aculeations. Vents respectively at 

 the ends of the tubular prolongations ? Internal structure soft, 

 composed of spicules held together by sarcode, traversed by 

 the excretory canal-system, which terminates at the vents 

 mentioned. Sarcode much yellower in the interior than on 

 the surface. Skeleton-spicules of three forms, viz. : — 1, very 

 large, long, and acuate, sub-pinlike, smooth, curved, sharp- 

 pointed, often bulbous, and sometimes doubly inflated at the 

 fixed end, 200- by 6|-1800ths inch (PI. XV. fig. 39, a)\ 2, sub- 

 skeleton-spicule or acerate, of a remarkable shape, viz. fusi- 

 form, nearly straight, inflated in the centre, once (sometimes 

 twice) obtuse at the extremities, which are respectively fis- 

 surate (that is, divided into three pointed arms approximated 

 at the points so as to form an apiculated termination) ; central 



