252 
THE VOYAGE OF H.M.S. CHALLENGEE. 
Geodia paujpera, Bowerbank. 
Geodia paupera, Bowerbank, Proc. Zool. Soc. Bond., p. 329, pl.xxxi. figs. 16-21, 1873. 
Sponge. — Massive, coating; surface even, finely hispid ; cortex, 0'48 mm. in thickness, 
ectocortex thin, transversed by cortical oxeas and containing minute chiasters (4) ; the 
inner fibrous layer of the cortex well defined, 0’06 mm. in thickness. 
Spicules. — I. Megascleres. 1. Somal oxea, I'l by 0*02 mm. 2. Cortical oxea, 0*254 
mm. long. 3. Orthotriaene, rhabdome 1 mm. long. 
II. Microscleres. 4. Sterraster, small, spherical, 0*054 mm. in diameter. 5. Somal 
chiaster, SiCtmQB cylindrical, truncate, 0*0054 mm. in diameter. 6. Choanosomal chiaster, 
actines slender, cylindrical, truncate, 0*024 mm. in diameter. 
Colour. — Cream-white in dried state. 
Habitat. — Unknown. 
Remarlcs. — This species is founded on a fragmentary specimen, scarcely complete 
enough for generic identification ; it appears however to bear oscules within a depressed 
area, like that of a true Geodia. 
Section 3. Ditrisena. 
Species from which cortical oxeas are absent ; but possessing anatrisenes or protriaenes, 
or both, in addition to orthotrisenes or dichotrisenes. 
Geodia Jlemingiiy Bowerbank. 
Geodia flemingii, Bowerbank, Proc. Zool. Soc. Bond., p. 3, pi. i. figs. 1-8, 1873. 
Sponge. — Massive, sessile, hollow within ; surface even, hispid ; oscules collected in a 
group near the base ; cortex 0*88 mm. in thickness ; ectochrote not seen, as the sponge 
is worn by attrition. 
Spicules. — I. Megascleres. 1. Strongyle, cylindrical, or fusiform, 1*6 by 0*029 mm. 
2. Dichotrisene, protocladus 0*06 mm. long, deuterocladus 0*052 mm. long. 3. Ana- 
triaene, rhabdome 0*008 mm. in diameter, cladus 0*084 mm. long, chord 0*078 mm. 
II. Microscleres. 4. Sterraster, more or less ellipsoidal, 0*1 mm. in diameter, 5. 
Somal spheraster, with short, cylindrical, truncate actines, 0*007 mm. in diameter. 6. 
Choanosomal spheraster, actines cylindrical, minutely spined, truncate ; 0*0254 mm. in 
diameter. 
Colour. — Light cream-yellow in the dried state. Size, 44 mm. long, by 33 mm. 
broad, and 37 mm. high. 
Habitat . — Port Elliot, Australia. 
