256 
THE VOYAGE OF H.M.S. CHALLENGED,. 
duced into numerous conical actines, 0'016 to 0‘019 mm. in diameter. 8. Choanosomal 
chiaster, actines slender, cylindrical, truncate, 0‘0197 mm. in diameter. 
Habitat. — Charles Island, Galapagos (Commander W. E. Cookson). In British 
Museum collection, labelled Stelletta E. 14. 
Cydonium berryi, n. sp. 
Sponge. — Small, spherical, oscules not distinguishable from the pores; pores 0'032 to 
0'045 mm. in diameter, in sieves overlying chones, which are about 0'16 mm. in 
diameter. Surface finely hispidated with cortical oxeas. Cortex 0'7 to 0*95 Tnrn, in 
thickness, consisting chiefly of the sterrastral layer. Megascleres of the choanosome 
radiating from the centre to the cortex. 
Spicules. — I. Megascleres. 1. Somal oxea, fusiform, sharply pointed, 2*54 by 0*026 
mm. 2. Ectosomal oxea, fusiform, 0*31 by 0*008 mm. 3. Orthotrisene, rhabdome conical, 
attenuating to an exceedingly fine point, 3*5 by 0*0516 mm., cladi 0*175 mm., chord 
0*318 mm. in length. 4. Protrisene, rhabdome fusiform, sharply pointed, 2*54 mm. 
long and over, by 0*0129 mm. just below the cladal origin, and 0*023 mm. where thickest; 
cladi 0*0516 mm. long. 5. Anatrisene, rhabdome conical, cylindrical, 0*258 mm. in 
diameter; cladi 0*084 mm., chord 0*1 mm., sagitta 0*065 mm. in length. 
II. Microscleres. 6. Sterraster, ellipsoidal, actines with flattened polygonal ends, 
furnished with recurved spines, 0*071 by 0*065 mm. 7. Ectosomal chiaster, actines short, 
cylindrical, truncated at the ends, from about six to twenty in number, 0*008 mm. in 
diameter. 8. Choanosomal chiaster, similar but larger, 0*012 to 0*015 mm. in diameter. 
9. Subcortical spheraster, small, centrum confluent with the actines, which are numerous, 
conical, and sharply pointed, 0*012 mm. in diameter. 
Colour. — In the dried state, grey. 
Habitat. — Lingin, China (Captain Berry, collection in British Museum, labelled 
4, 27, 73). 
Remarks. — The single specimen of this species is constricted in the middle, so as to 
appear like two spheres joined together. Minute anatrisenes like those observed on 
Cydonium gigas were seen projecting from the surface, one which extended 0*16 mm. 
beyond the cortex gave the following measurements : — Ehabdome 0*002 mm. in diameter, 
cladi 0*008 long, chord 0*0095 mm. I dedicate the species to Captain Berry, who 
brought it home from China. 
Cydonium japonicum, n. sp. 
Sponge. — Large, cup-shaped, sessile, the inner surface even, the outer growing out into 
rounded lobes; both surfaces minutely hispidated by cortical oxeas. Incurrent and ex- 
