310 Mr. H. J. Carter on Deep-sea 



form, while the loose structure of the internal parts, unattended 

 by any dense axial arrangement, is more like the Halichon- 

 drina. Pending the examination of a perfect specimen, which, 

 I expect, from the delicate structure of the internal contents in 

 all the " histodermal " sponges, is not likely to be soon ob- 

 tained, I think this sponge had better be placed provision- 

 ally in the second division of the Echinonemata. In all the 

 specimeps the protruding head being fringed out, probably by 

 friction and decomposition, thus fails to present the original 

 form. 



HalicJiondria foliata^ Bk. [p^. cit. vol. iii. pi. 73. fig. 1). 

 (PL XIL fig. 10, and PI. XV. fig. 29, a, 5.) 



Of this sponge there is only a fragment by itself in a jar 

 numbered 65, which station is a little N.W. of the Shetland 

 Islands. It is about | inch square and i inch thick, and be- 

 longed to a compressed, erect or vertical sponge entirely com- 

 posed of a reticulated, anastomosing structure, whose inter- 

 stices are open from side to side — that is, directly through the 

 sponge fenestrally. The reticulated fibre, which is ragged 

 and hirsute from the projection of spicules, is now of a pale 

 whitish-yellow colour. Pores and vents not evident. Spicules 

 of two kinds, viz. skeleton- and flesh-spicules. Large skele- 

 ton-spicule acuate, smooth, sharp-pointed towards the large 

 end, 94- by 4-6000ths inch (PI. XV. fig. 29, a) ; small or 

 subskeleton-spicule also acuate, smooth, sharp-pointed, in- 

 flated at the large end, scantily spined over the extremity, 78- 

 by l-6000th inch (fig. 29, V). Flesh-spicules of two forms, 

 viz. : — 1, equianchorate, navicular or shuttle-shaped,4-6000ths 

 inch long (PI. XII. fig. 10, a) ; and, 2, a tricurvate, whose 

 arms are very thin and spread out horizontally to a great 

 extent, with a sudden bend in the centre, often converted into 

 a loop, 140-6000ths inch long (fig. 10, h). It is by the pro- 

 jection of the large skeleton-spicules chiefly that the hirsute 

 surface is produced. The remarkable form and size of the 

 tricurvate are not confined to this sponge ; for they are to be 

 found in Microciona armata^ Bk. ; but here the ends are spini- 

 ferous. I learn this more particularly from a mounted speci- 

 men of this sponge which I have found here (Budleigh- 

 Salterton) . 



Isodictya spinispiculum, n. sp. (PI. XV. fig. 42.) 

 On the rotigh flat stone bearing a specimen of Macandrewia 

 azorica before mentioned, with one of Geodia nodastrella, n. sp., 

 to be hereafter described, is a portion oi Isodictya spimspiculum. 



