120 THE VOYAGE OF H.M.S. CHALLENGER. 



elaboration of the bipocillate spicules. The other spicules are also larger in almost 

 every case than the corresponding forms in other species of lojihon ; lophon [Alehion) 

 piceum, Vosmaer, approaches it the most nearly in this respect, but even in this species 

 the stylus measures only 0'32 mm. in length. 



Localities. — Station 142, December 18, 1873 ; lat. 35° 4' S., long. 18° 37' E. ; off 

 the Cape of Good Hope ; depth, 150 fathoms ; bottom, green sand ; bottom temperature, 

 47°. The young specimen. 



Station 145a, December 27, 1873 ; lat. 46° 41' S., long. 38° 10' E.; off Prince Edward 

 Island; depth, 310 fathoms ; bottom, volcanic sand. 



Station 148a, January 3, 1874 ; lat. 46° 53' S., long. 51° 52' E. ; between Prince 

 Edward and Kerguelen Islands ; depth, 550 fathoms ; bottom, hard ground, gravel, 

 shells. 



lophon cylindricus, Ridley and Dendy (PL XVI. fig. 4 ; PI. XVII. fig. 6). 



1886. lophon cylindricus, Eidley and Dendy, Ann. and Mag. Nat. Hist., ser. 5, vol. xviii. p. 319. 



Sponge (PI. XVI. fig. 4) erect, cylindrical (whence the specific name), with expanded 

 base encrusting a dead Pecten shell ; showing a slight tendency, to branch at the apex. 

 Height, including base, 44 mm. Average diameter 6 mm. (A second specimen, 

 also growing on a dead shell, appears to represent little more than the base of the 

 sponge.) Colour in sj)irit brown. Texture brittle and crumbling. Dermal memhrane 

 very distinct, transparent', and with numerous round pores. Oscula scattered over the 

 surface (?). 



Skeleton. — (o) Dermal ; a very well developed network of not very closely aggre- 

 gated tylota. (h) Main ; a reticulation of loose spiculo-fibre, composed of stylote 

 spicules. 



Spicules. — (o) Megasclera ; slightly curved, smooth styli (PL XVII. fig. 6, a, h), 

 each tapering from near the apex to a very sharp point; size 0"25 to 0"29 by 0*011 

 mm. {h) Micvosclera ; of two kinds ; (1) palmate anisochelee of the usual lophon tyj)e, 

 measuring 0'025 mm. in length ; (2) bipocilli, numerous and of the usual shape, 0'0127 

 mm. long. 



It will be seen that this species approaches Iop>hon laminalis, nobis, in the smoothness 

 of the styli, but the external form is very different. Further, the tylota are little more 

 than half as stout, and the styli only half as stout and not half as long as the corre- 

 sponding spicules in that species. 



Locality/. — Station 163a, April 4, 1874 ; lat. 36° 59' S., long. 150° 20' E.; north- 

 east of Cape Howe, Australia; depth, 120 fathoms; bottom, green mud. Two 

 specimens. 



