REPORT ON THE TETRAOTINELLIDA. 
269 
II. Microscleres. 3. SterrasteVy spherical, 0’213 mm. in diameter. 4. Oxyaster, 
with few remarkably slender actines. 
Colour . — (?). 
Habitat. — Florida ; depth, 153 fathoms. 
Remarks. — The description has been chiefly taken from Schmidt’s account. The 
measurements of spicules are from a type-slide in the British Museum. Schmidt makes 
no mention of triaenes, but that is no reason for inferring they are not present. The 
sponge may represent a new genus, but it can hardly be assigned to Caminus. 
I sops imperfecta (Bowerbank). 
Geodia imperfecta, Bowerbank, Proc. Zool. Soc. Bond., p. 299, pi. xlvi. figs. 6-13, 1874. 
Sponge. — Massive, tuberous, sessile ; surface smooth ; oscules scattered, small, circular. 
Ectochrote characterised by peculiar spherasters (No. 4). Cortex 1'43 mm. in thickness. 
Spicules. — I. Megascleres. 1. Oxea, fusiform, bluntly pointed, often strongylate ; 
1'75 by 0’039 mm. 2. Orthotrisene, cladi usually strongylate, frequently reduced to 
two or one in number. 
II. Microscleres. 3. Sterraster, ellipsoidal, depressed, or more or less cylindrical, with 
rounded ends, OTl by 0'08 mm. 4. Ectochrotal spheraster, centrum well developed, 
actines short, cylindrical, divided into numerous spines at the ends; 0‘012 to 0’019 mm. 
in diameter. 5. Somal spheraster, centrum small ; actines slender, cylindrical, truncate, 
proceeding from the centrum abruptly; 0'021 mm. in diameter. 
Colour. — Cream- white in the dry state. Size, the largest of four specimens, 50 mm. 
long by 35 mm. broad. 
Habitat. — South Sea ; growing on Oculina rosea, obtained from a dealer. 
Isops dysoni (Bowerbank). 
Geodia dysoni, Bowerbank, Proc. Zool. Soc. Bond., p. 14, pi. iii. figs. 1-5, 1873. 
Sponge. — Massive, sessile (?). Surface smooth, uneven ; cortex about 1 mm. in 
thickness, chiefly composed of the sterrastral layer. 
Spicules. — I. Megascleres. 1. Oxea, 1‘75 by 0'026 mm. 2. Orthotrisene, rhohdomc, 
1'6 by 0'032 mm., cladi 0'35 mm. in length. 
II. Megascleres. 3. Sterraster, spherical, depressed, 0’095 mm. in diameter. 4. 
Somal aster (J). 5. Choanosomal chiaster, actines slender, cylindrical, truncate ; 
0‘024 mm. in diameter. 
Colour. — Cream-white in the dried state. Size, 75 mm. by 40 mm. (Bowerbank). 
Habitat. — Honduras. 
