Sponges from the Atlantic Ocean. 233 



compressed and expanded at the distal extremities, the ter- 

 minal ones short, fork-like, but round at the ends ; stem below 

 the branches short, thick, expanded at the base. Colour 

 yellowish white or dark brown. Surface even, hirsute (fig. 

 3, a) . Pores and vents indistinct. Internal structure compact, 

 increasing in density towards the axis, composed of spicules 

 held together by cellular sarcode, which again is traversed by 

 the excretory canals. Spicules of two kinds, viz. skeleton- 

 and flesh-spicules. Skeleton-spicules of two forms, viz.: — 1, 

 large, acuate, attenuatingly pointed, bent or suddenly curved 

 towards the large end, 92- by l^-lSOOths inch (PI. XV. 

 fig. 25, a) • 2, subskeleton, sub-pinlike, smooth, attenuatingly 

 pointed, nearly straight, sparsely microspined at the extremity 

 of the inflated end, 45- by i-lSOOths inch (fig. 25, b). Flesh- 

 spicules of three forms, viz. : — 1, acuate, club-shaped, attenu- 

 atingly pointed, bent towards the large end, sparsely spined 

 throughout, spines vertical, 19- by l-1800ths inch (PI. XII. 

 fig. 3, b) • 2, equianchorate, shuttle-like, with nearly straight 

 shaft— 6-6000ths inch long by li-6000ths inch broad at the 

 arms (fig. 3, c & f) ', 3, tricurvate or bow-shaped, smooth, 

 with pointed and spined extremities, 26-1800ths inch long 

 (fig. 3, d,e). The large acuates form the chief part of the 

 stem, where they are arranged vertically, while others are 

 projected through the dermal sarcode at right angles to them, 

 and thus give the hirsute character to the surface ; the sub- 

 pinlike spicule projects at the base of the latter, and the 

 spined acuate flesh-spicules at their base again, appearing just 

 beyond the dermal sarcode ; while the equianchorate and bow- 

 shaped flesh-spicules are dispersed generally throughout the 

 structure. Size of largest entire specimen (of which there are 

 two) 3^ inches long by 2 4 inches broad ; stem at the bottom 

 I inch long and | inch thick. 



Hab. Marine, attached by an expanded base to hard objects. 



Loc. Between the north of Scotland and the Faroe Islands, 

 in 440 and 345 fathoms. 



Obs. There are two specimens of this sponge, obtained 

 respectively from stations 51 and 65, as indicated by the 

 numbers on their respective jars. These numbers give the 

 depths and locality above mentioned. The smaller specimen 

 is alone, in the jar numbered " 51 ;" while the other not only 

 has a portion of Halichondria Hyndmani on one of its branches, 

 but in the jar are ?A'&o Pachastrella abyssi, Wyville-Thomsonia 

 Wallichii, and all the specimens on the Terebratule and 

 pebble mentioned under Sj)ongia officinalis. 



In several of the order Echinonemata, and especially of the 

 branched forms of which Dictyocylindrus abyssorum is one, 



