SILICIOUS AND HORNY SPONGES WILSON. 389 



Two dried specimens of the Albatross collection are assignable 

 to this species, one from station D5626, the other from Togian Bay, 

 Togian Island, Gulf of Tomini. Celebes; also two alcoholic speci- 

 mens from Togian Bay. They differ, however, from the records 

 in a marked anatomical feature — namely, the possession of strong 

 longitudinal spicule-traets — and may on that account be referred 

 to a variety, fibrosa, new variety. The sponges are much taller than 

 those recorded, the oxeas considerably smaller, and the sigmas are 

 at the lower limit of the range recorded, which is considerable. 



Sponge body consists of a branching axis, which may be cylin- 

 drical, or distinctly flattened, the branches often meeting and fus- 

 ing and terminating in pointed extremities. Where the sponge is 

 more cylindrical the diameter is 5-7 mm. In one of the typical 

 flattened regions the diameters are 20 mm. and 7 mm. Total height 

 reaches 300-400 mm. Sponge firm but brittle; color of dried sponge, 

 light gray or light yellowish brown ; color of alcoholic specimens, 

 reddish brown. The photograph, (pi. 40, fig. 3), shows a very flat- 

 tened piece, a moderately flattened piece, and a terminal cylindrical 

 branch, side by side, all from a dried specimen. 



Pores are closely and uniformly distributed over the surface in 

 the meshes of the dermal reticulum. Abundant small afferent 

 canals, about 0.5 mm. in diameter, extend in radially from the 

 surface and give the sponge a porous appearance. Oscula about 

 2 mm. in diameter are abundantly scattered over the surface, lead- 

 ing into well-marked depressions into which several efferent canals 

 directly debouch. 



The skeleton is made up of a renieroid reticulum and longitudinal 

 polyspicular tracts, often compact enough to deserve the name of 

 fibers, 20-100 pt in diameter. They consist of closely packed spicules 

 in about 3 to 12 rows; they branch* and anastomose obliquely so 

 as to form a coarse and rather vague network with elongated meshes. 

 The longitudinal tracts were conspicuous in all the sections made, but 

 are considerably more abundant and closely set in some regions than 

 in others. They are especially developed in, though by no means 

 confined to, the axial part of the sponge. Thus in a typical region 

 where the total diameter of the sponge is 7 mm., the longitudinal 

 tracts occupy an axial portion about 4 mm. wide. Their distribu- 

 tion varies however in the same specimen (perhaps with the age 

 of the region), and a considerable number may occur in the super- 

 ficial part of the body. Indeed, in some sections in which they 

 were rather sparsely present, the tracts were quite as abundant in 

 the peripheral as in the axial part of the body. 



The rest of the skeleton is in general made up of a renieroid re- 

 ticulum, with 4 or 3 sided meshes, the side about the length of a 

 spicule and formed by one or sometimes two spicules (pi. 49, fig. 1). 



