REPORT ON THE MONAXONIDA. 163 



Echinoclatliria glabra, Ridley and Dendy (PI. XXIX. figs. 11, 11a ; PI. XXXI. fig. 2). 



1886. Echinoclatliria glabra, Ridley and Dendy, Ann. and Mag. Nat. Hist., ser. 5, vol. xviii p. 476. 



Sponge (PI. XXXI. fig. 2) massive but honeycombed throughout, consisting 

 throughout of thin, flattened trabeculse, anastomosing and interwoven with one another, 

 leaving oval or rounded meshes about 4 mm. in diameter. The single specimen in the 

 collection is about 112 mm. high by 75 mm. broad, and 44 mm. thick ; it has evidently 

 been cut off at the base. Colour in spirit yellow. Texture firm and parchment-like. 

 Surface (of the trabeculse) glabrous. Dermal membrane thin, transparent, very rarely 

 stretching across the mouths of the cavities at the surface. Oscula not observed, 

 apparently the sponge is lipostomous. 



Skeleton. — A reticulation of well-developed horny fibre, sparsely cored by tylota and 

 sparsely echinated by smooth subtylostyli. 



Spicules. — Megasclera; (1) smooth, fusiform subtylostyli (PI. XXIX. fig. 11a), 

 sharply and gradually pointed at the apex and constricted before the head, which is no 

 wider than the shaft; size about O'll by 0"006.3 mm.; echinating the horny fibre. 

 (2) Long, smooth tylota (PI. XXIX. fig. 11), very slender, with oval heads; measuring 

 about 0*22 by 0'0032 mm., in the fibre and scattered, especially on the surface of the 

 trabeculse. 



This species is distinguished by its glabrous surface and by the presence of the 

 tylote spicules in the fibre and scattered. No microsclera are present. It is very probable 

 that, owing to its spicular peculiarities, it ought to form the type of a new genus, but 

 we prefer to leave the responsibility of this step to some one who has a larger series of 

 forms for comparison than we have. 



Zoca%.— Station 162, April 2, 1874 ; lat. 39° 10' 30" S., long. 146° 37' 0" E.; off 

 Moncoeur Island, Bass Strait; depth, 38 fathoms; bottom, sand and shells. One 

 specimen. 



Genus Agelas, Duchassaing and Michelotti (PI. XXIX.). 



1864. AgelaSj'Dvich. and Mich., Naturkund. Verhand. Maatschapp. te Haarlem, ser. 2, vol. xxL p. 76. 

 1867. Ecfyon, Gray, Proc. Zool. Soe. Lond., p. 515. 



1870. Chalinopsis, Schmidt, Spong. Atlant. Gebiet., p. 59. 



Of various form ; with well developed horny fibre echinated by verticillately spined 

 stylote spicules. No microsclera and no other megasclera. 



To Carter is due the merit of having pointed out ^ that Ectyon sparsus. Gray, is referable 

 to the older genus Agelas of Duchassaing and Michelotti, nevertheless he retains Gray's 

 generic name, Ectyon; in this we cannot, with due regard to the rules of priority, 



1 Ann. and Mag. Nat. Hist, ser. 5, vol. is. p. 281. 



