On Deep-sea Sponges from the Atlantic Ocean. 245 



XXXI. — Descriptions and Figures of Deep-sea Sponges and 

 their Spicules from the Atlantic Ocean, dredged up on board 

 H.M.S. l Porcupine,' chiefly in 1869/ with Figures and De- 

 scriptions of some remarkable Spicules from the Agulhas 

 Shoal and Colon, Panama. By H. J. Carter, F.It.S. &c. 



[Concluded from p. 221.] 



Halichondria abyssi, n. sp. PI. XIV. figs. 26-28, and 

 PI. XV. fig. 40, a, b, c. 



General form unknown. Sessile, spreading horizontally. 

 Colour grey or brown. Internal structure massive, consisting 

 of an areolar skeleton formed of polygonally arranged bundles 

 of spicules covered with sarcode (PI. XIV. fig. 26). Spicules 

 of two kinds, viz. skeleton- and flesh-spicules. Skeleton- 

 spicules of three forms, viz. : — the longest, smooth, curved, 

 fusiform acerate, fine-pointed, average largest size 45 by 

 f -1800th inch in its greatest diameters (PI. XV. fig. 40, a) ; 

 shorter spicule, stout, smooth, acuate, curved, rather abruptly 

 pointed, averaging in its largest size 35 by 1-1 800th inch 

 in its greatest diameters (fig. 40, b) ; smallest form smooth, 

 curved, fusiform, inflated equally at each extremity, average 

 largest size 22 by ^-1 800th inch in its greatest diameters 

 (fig. 40, c). Flesh-spicules of two forms, viz. equianchorate 

 and tricurvate. Equianchorate (PI. XIV. fig. 27, a, b) : shaft 

 round, much curved, almost bent, expanded but not alate at 

 the ends, where the expansion extends into a claw- or clam- 

 shaped umbrella-like head, composed of six linear recurved 

 arms webbed together nearly to the extremities ; average 

 largest size 16 by 3-6000ths inch in its greatest diameters, 

 viz. length of shaft and width of head respectively. Tricur- 

 vate (fig. 28) stout, 18 by l-6000th inch in its greatest 

 diameters. Size of entire fragments each about \ inch in 

 diameter and l-12th inch thick. 



Hab. Deep sea, on deciduous shells. 



hoc. Atlantic Ocean. Between the north coast of Scotland 

 and the Faroe Islands. 



Obs. The jars containing these two fragments respectively 

 bear the No. " 65, ,: which station gives a depth of 345 

 fathoms. That in the smaller jar is of the least consequence, 

 being a mere unconnected formless fragment of a brown 

 colour ; while the other (which is figured) has grown over the 

 concavity of a small ostraceous bivalve shell (fig. 26, b) , and 

 is of a lighter colour, but at once reveals the structure and 

 habitat of the sponge, although, from being only a fragment 



