426 
THE VOYAGE OF H.M.S. CHALLENGEK. 
Genus Dorypleres, n. gen. 
As this is the only genus I refrain from giving a diagnosis. 
Doripleres dendyi, n. sp. (PI. XLII. figs. 12-19). 
Sponge (PI. XLII. fig. 12). — An irregular hollow cylinder, with walls of unequal 
thickness, open at both ends. Surface hispid in places, especially near the base, else- 
where covered by a smooth shining membrane, marked by deep branching grooves, 
arranged in stellate groups. Oscules small, situated in the floor of the superficial 
grooves. Pores small, singly distributed. 
Spicules. — I. Megascleres. 1. Somal oxea (PI. XLII. fig. 13), fusiform, thick, 
straight or curved, oxeate or tornote, 2'06 by 0‘097 mm. 
2. Ectosomal (hispidating) strongyloxea, cylindrical, 1'12 by 0’013 mm. 
II. Microscleres. 3. Somal spTieraster (PI. XLII. figs. 14-17), centrum somewhat 
small, about 0‘015 mm. in diameter; actines conical, oxeate, about ten in number, 
sometimes more numerous, sometimes reduced to two, total diameter O'l mm. 
4. Ectosomal spheraster, centrum, though absolutely smaller, relatively larger than 
in the preceding spicule, O'OllS mm. in diameter ; actines conical, oxeate, about eighteen 
to twenty in number, total diameter 0‘04 mm. 
Colour, — Greyish-white. 
Habitat . — Station 192, September 26, 1874; lat. 5° 49' 15" S., long. 132° 14' 15" E.; 
depth, 140 fathoms ; bottom, blue mud. Trawled. 
Remarks. — The single specimen of this sponge, which is complete, measures 45 mm. 
in diameter, and 37 mm. in height, the central cavity is 18 mm. wide, the wall on one 
side 20 mm. in thickness, on the other 7 mm. 
The somal oxeas are thickly scattered through the sponge, apparently without any 
trace of arrangement ; where they cross each other they are usually bound together by 
spongin. It is impossible to cut thin slices of this sponge, the spicules tearing the 
tissue to rags. From such observations as I was able to make, the choanosomal meso- 
derm appeared to be collenchymatous, and I conclude that the flagellated chambers are 
probably eurypylous. The somal spherasters occur throughout the sponge, but imme- 
diately beneath the skin they are supplemented by the smaller ectosomal spherasters. 
The pores vary from about 0’02 to 0*04 mm. in diameter. The stellate systems of 
grooves on the surface are remarkably similar to those which occur in the case of several 
Lithistid sponges. 
Amongst the spicules obtained from the sponge by boiling out with nitric acid are a 
few small tylotoxeas (PI. XLII. figs. 18, 19), which may possibly belong to it, but may 
quite as probably be foreign inclusions. 
