92 
THE VOYAGE OF H.M.S. CHALLENGER. 
Characella aspera, SoUas (PL XL. fig. 6). 
Characella aspera and Normania golioih, Sollas, Prelim. Account, Sci. Proc. Roy. Dubl. Soc., 
vol. V. pp. 186, 187, 1886. 
Sponge (PI. XL. fig. 6), irregular in form, growing into irregular ridges, lobes, and 
folds ; the furrows between the ridges sometimes prolonged as tubes into the interior. 
Oscules numerous, the freely open ends of large excurrent canals, situated on the sides 
and summits of the ridges. Pores numerous, dispersed generally, or collected into circular 
depressed areas. Surface rough, hispid with projecting oxeas and orthotrisenes. 
Spicules. — I. Megascleres. 1. Oxea, massive, fusiform, usually slightly curved, not 
sharply pointed ; 2’476 by 0’073 mm. 
2. Orthotrisene (and dichotrisene), a conical not sharply pointed rhabdome ; cladi 
simple or bifurcate, projecting outwards and more or less forwards ; rhabdome 0'2 to 0'4 
by 0 '024 to 0’047 mm. ; cladi, when simple, 0 ‘2 to 0 ‘63 mm. long ; when bifurcate, 
protocladi 0'143, deuterocladi 0'27 mm. long. 
II. Microscleres. 3. Microxea, fusiform, straight or curved, sharply pointed, smooth ; 
0’32 by O'OOS mm. 
4. Ampliiaster, a short fusiform axis, with a whorl of four to six conical sharply 
pointed spines, and a single spine continuing the direction of the axis at each end ; 
0'0276 to 0'0434 mm. long ; axis about 0‘008 mm. long, spines from O'OllS to 0‘0237 
mm. long. 
5. Globules, about 0'048 to 0'16 mm. in diameter, occasionally present. 
Colour. — Greyish or yellowish- white. 
Habitat. — Station 122, September 10, 1873 ; lat. 9° 5' S., long. 34° 50' W.; depth, 
350 fathoms ; bottom, red mud. Trawled. 
RemarJcs. — Two fragments of this sponge were obtained, the larger about 60 by 80 
mm. in breadth and width, and about 25 mm. thick ; when complete it must have been 
thicker as the under surface is broken. 
The large oxeas lie irregularly scattered through the sponge ; but near the surface 
many of them are disposed perpendicularly and project beyond it. Horny matter is 
sometimes found associated with them, as in Pcecillastra. The trisenes are confined to 
the exterior and are not numerous there, they lie with the rhabdomes at right angles to 
the surface, the cladi directed towards it, and either extended beneath or outside it. 
The microxeas are thickly dispersed in all directions through the tissues of the sponge, 
forming a kind of felt ; they exhibit a general tendency to lie tangentially to the walls of 
the canals. They are evidently the homologues of the microxeas of Peecillastra. 
The amphiasters are not numerous, they occur beneath the epithelium of the canals, 
and especially around the margins of the pores. They evidently represent the spirasters 
of Pcecillastra. 
