Sponges from the Atlantic Ocean. 319 



Cladorhlza abyssicohi^ Surs, var. corticocancellata. n. .sp. 

 (PI. Xlll. fig. 16.) 



General f<inn sliort-branclied slinibhj stems, covered with 

 a thiek eaneellated eortex, ecliinated with .short, erect, spiue- 

 like processes ; ends of the branches tumid, round. Colour 

 cream-yellow in spirit. Surface irregular, cancellate, with the 

 holes bonlercd by short spine-like processes, which consist of 

 pointed bundles of spicules. Pores in the dermal sarcode 

 covering the cancellated structure. Vents indistinct. Internal 

 structure consisting oi' the axis or stem, which is hard, com- 

 pact, and colourless, being composed of spicules of the species 

 closely approximated and arranged together longitudinally 

 and parallel to each other, tending to the formation of a spiral 

 cord, at right angles to which bundles of spicules issue, sup- 

 porting (as they branch outwards and terminate on the spine- 

 like processes of the surface) the cancellated sarcodic substance 

 of the cortex, traversed by the branches of the excretory canal- 

 system, whose openings at the vents have been stated to be 

 indistinct. Spicules of two kinds, viz. skeleton- and flesh- 

 spicules. Skeleton-spicule of one form only, viz. acuate, 

 fusiform, attenuatingly pointed, smooth and nearly straight, 

 head less in diameter than the body, 100- by 1-I800th inch. 

 Flesh-spicules of two forms, viz.: — 1, inequianchorate, exactly 

 like that of C. ahyssicola (' Annals,' 1874, vol. xiv. pi. 14. 

 tig. 22) ; 2, bihamate or fibula, simple, smooth, with nearly a 

 Btraight back or shaft and a prolonged, whip-like, everted end 

 to each extremity, 39- by l-6000th inch (PI. XIII. fig. 16, a). 

 The skeleton-spicules are chiefly confined to the stems and 

 branches supporting the sarcode, while the largest are in the 

 former, and the flesh-spicules scattered profusely (especially 

 the inequianchorate) throughout the sarcode generally. Size 

 of entire sponge unknown, as the specimens are all in frag- 

 ments. 



Ilab. Marine. 



Loc. Between the north of Scotland and the Shetland and 

 the Faroe Islands, in 345 and 632 fathoms. 



Obs. There are four jars containing specimens of Clado- 

 rhiza al)y8sicola, Sars, and C corticocancellata^ all more or 

 less fragmentary and mixed together, and all bearing the same 

 number, viz. " 57," which gives the locality and depth above 

 mentioned : add to these another jar, No. ijOj which gives a 

 locality about 40 miles N.N.W. of tiie Shetland Islands in 345 

 fathoms, containing a single specimen of C. abyssicola so 

 different in form to all the rest, tliat it requires the short and 

 separate description which will be given presently. 



