196 
THE VOYAGE OF H.M.S. CHALLENGED, 
Ecionema acervus, Bowerbank. 
Edonema acervus, Bowerbank, Brit. Spong., vol. i. p. 173, pi. xxviii. fig. 355, 1864; Proc. Zool. 
Soc. Lond., p. 322, pi. xxx. figs. 1-6, 1873. Non Eidley, Spong. 
“Alert,” p. 627. 
Sponge. — Pear-shaped, massive, pedicelled (?) ; surface even, minutely hispid ; oscules 
dispersed. 
Spicules. — I. Megascleres. 1. Oxea, fusiform, abruptly pointed, 4'0 by 0’067 mm. ; 
the oxeas occurring in the axis of the sponge are smaller, 27 by 0‘084 mm. 2. Ortho- 
triasne, rhabdome, esactine strongylate, 3‘03 by 0 084 mm., cladi 0‘270'mm. in length. 
3. Anatriaene, rhabdome 4 0 by 0‘029 mm., cladi 0 097 mm., chord 0'116 mm. long. 
II, Microscleres, 4, Microstrongyle, fusiform, 0‘009 by 0’0026 mm. 5. Chiaster, 
with terminally tylote actines, 0'008 mm. in diameter. 6. Spheraster, 0‘008 mm. in 
diameter. 
Colour. — Dark brown in the dried state. 
Habitat. — Fiji. 
Remarks. — The sponge measures 56 mm. in height by 48 mm. in width ; the base is 
broken off. The microstrongyles, usually smooth and not spined, form a layer beneath 
the outer epithelium, and are the predominant microsclere of the choanosome also. 
Minute oxeas are present in the ectosome ; I have no note of their dimensions. 
Ecionema gustraliense (Carter). 
Stelletta australiensis, Carter, Ann. and Mag. Nat. Hist., ser. 5, vol. xL p. 350, pi. xiv. fig. 2, 
1883. 
Sponge. — Large ; ectosome thin ; oscules and pores (?). 
Spicules. — I. Megascleres. 1. oicea, sometimes a strongyle, 2T8 by 0'055 mm. 
2. Ectosomal oxea, 0‘5 by 0'006 mm. 3. Protriaene, rhabdome pointed, or frequently 
strongylate ; cladi also pointed or strongylate. Rhabdome 2'22 by 0‘05 mm., cladi 
0’2 mm,, chord from 0‘095 to 016 mm. long. 4. Anatriaene, rhabdome pointed or 
strongylate, 2’22 by 0’013 mm.; cladi short, frequently strongylate, 0’032 mm. in length. 
II. Microscleres. 5. Microstrongyle, fusiform or cylindrical, faintly centrotylote, 
0’009 mm. in length. 6. Chiaster, actines slender, hair-like, terminally tylote, a 
minute spherical centrum sometimes present, total diameter, 0’012 nun. 
Colour. — (?) Size, 300 mm, in height by 187‘5 mm. broad, and 75 mm. thick at the 
base. 
Habitat. — Freemantle, west coast of Australia. 
Remarks. — Mr. Carter has kindly afforded me an opportunity of examining mounted 
preparations of this species ; it is an evident Ecionema, and represents in that genus the 
species Anthastra ridleyi amongst the Anthastrae. 
