458 COLLECTIONS FEOM MBLANHSIA. 



the present form provisionally to that species, with -which it agrees 

 much better than the form which I named E. nervosum ( Joum. Linn. 

 Soc, Zool. XV. p. 496). As to the locality at which 8. caneellata 

 was obtained, we have no more particular knowledge than that it 

 was obtained by MM. Peron and Lesueur. As these travellers seem 

 to have coUeeted, among other places, on the north coast of Australia, 

 this fact supports, if any thing, the aliove view as to its identity with 

 the present species. In any case it will be best to describe the latter 

 fully : — ^Erect, flabellate, clathrous. A short main stem gives rise 

 to a clathrous reticulation lying in one plane, in which the original 

 branches are only distinguishable near the base. Reticulation close, 

 regular; meshes oval, the longest diameter lying in direction of 

 long axis of sponge, about 10 by 5 millim. ia average dimensions ; 

 the meshes form deep cells, occasionally closed by a septum of 

 sponge-substance. The stem, branches, and the bars which com- 

 plete the reticulation are oblong in transverse section, with rounded 

 margins ; hence the lateral surfaces are flat and the antero-posterior 

 ones are rounded. Antero-posterior diameter of stem 32 miUim., 

 lateral diameter 18 millim. ; antero-posterior diameter of the bars 

 which form the ultimate reticulation about 10 millim., lateral di- 

 ameter about 6 millim. A slight tendency to proliferation so as to 

 form expansions parallel to the main plane of the sponge is shown 

 by formation of a few meshes on the surfaces of the frond. Termi- 

 nations of branches either united by connecting bars or projecting 

 slightly as rounded lobose ends. Surface in dry (macerated) state 

 quite even, appearing minutely reticulate. Texture firm, that of 

 stem woody ; substance of branches and reticulation rather brittle, 

 slightly compressible ; colour, in macerated condition, very pale 

 yellow-brown. 



Main skeleton rectangular in arrangement ; primary fibres only pro- 

 jecting from surface by the tuft of echinating spicules which termi- 

 nates them, compact, about 8 to 10 spicules broad ; distance between 

 them at surface about -4 mUlim. ; echinated sparsely in interior, 

 abundantly near surface of sponge, with the echinating spicule : 

 secondary fibres compact, about 3 to 6 spicules broad, about 

 •3 millim. apart, echinated abundantly with the echinating spicule. 

 Dermal skeleton consisting of an irregular network with rectangular 

 meshes, the meshes generally not exceeding "55 millim. in diameter; 

 fibre compact, about 10 spicules broad, well echinated with the 

 echinating spicule. Horny uniting material occasionally distin- 

 guishable outside fibre as a pale yellow transparent substance. 

 Barcode? (absent). Spicules : — (1) Skeleton acerate, smooth, sUghtly 

 curved, tapering to sharp points from within about four diameters of 

 the ends ; size "22 by •0127 millim. (2) Echinating cylindrical, 

 spin'ed ; both ends well rounded ; spicule tapering slightly from 

 base to apex ; the apex about half the diameter of the base ; spines 

 distributed all over the spicule, rather more abundantly at base 

 and near apex than elsewhere ; those of the proximal half or one 

 third of the spicule rather small, straight, sharp, the remainder 

 longer, curved towards base ; size of spicule -15 by 'Ol millim. : scat- 



