266 
THE VOYAGE OF H.M.S. CHALLENGER. 
Colour. — A deep cream-yellow. Size, 263 mm. long by 225 mm. wide by 137 mm. 
high. 
Habitat. — Vigten Island, Norway ; depth, 100 fathoms (Kev. Dr. Norman’s collec- 
tion). 
Section Monotriaena. 
Synops (?) media, Bowerbank. 
Oeodia media, Bowerbank, Proc. Zool. Soc. Lond., p. 13, pL ii. figs. 34-29, 1873. 
Sponge. — Massive, sessile ; oscules comparatively large ; cortex 0*56 mm. in thick- 
ness, composed chiefly of sterrasters ; ectochrote thin, containing minute asters (No. 5). 
Spicules. — I. Megascleres. 1. Oxea, 1’51 by 0'032 mm. 2. rhabdome 
1'12 by 0*45 mm., cladi 0'254 mm. long, chord 0'32 mm. 
II. Microscleres. 3. Sterraster, ellipsoidal, O'll by 0 '08 8 mm. 4. Somal spheraster, 
minute, with truncated cylindrical actines, 0‘006 mm. in diameter. 5. Choanosomal 
oxy aster, 0*026 mm. in diameter. 
Colour. — Pale bufiF-yellow in the dried state. Size, about 20 by 30 mm. 
Habitat . — Mexico. 
Remarks. — The presence of large, simple, congregated oscules distinct from the pores 
leads us to assign this species to Synops. The measurements of the spicules were made 
from type-slides in the British Museum. 
Synops pyriformis, Vosmaer. 
Synops pyriformis, Vosmaer, Spong. “ Willem Barents,” p. 20, pi. iii. figs. 52-63 ; pi. iv. 
figs. 119, 154, 1882. 
Sponge. — Pyriform, small roots proceeding from the base ; oscules confined to a de- 
pression on the summit ; surface strongly hispid by the projection of the radial oxeas. 
Cortex 1*25 to 1*5 mm. thick, ectochrote reduced to a single layer of subepithelial 
spherasters. 
Spicxdes. — I. Megascleres. 1. Oxea, fusiform, often becoming strongylate,* 6*6 by 
0*08 mm. 2. Orthotrisene, 5*4 by 0*09 mm., chord 1*43 mm. 
II. Microscleres. 3. Sterraster, ellipsoidal, about 0*13 by 0*10 mm. 4. Somal spher- 
aster, with a well-developed centrum produced into numerous conical, sharply pointed 
actines, 0*016 mm. in diameter. 5. Choanosomal oxy aster, actines stout, conical; 0*07 
mm. in diameter. 
Colour. — Pale ochreous to faintly pink. Size, 120 mm. in height by 100 mm. in 
maximum diameter. 
Habitat. — Lat. 71° 12' N., long. 20° 30' E. ; near Hammerfest; depth, 135 fathoms. 
