﻿jg5 "ENDEAVOUR" SCIE>fTIFIC RESULTS. 



(/) ]'ar. OBESUS, nam. nov. 



1901. Chiihria typica, Whitelegge, Rec. Austr. Mus., iv., 2, 

 1901, p. 80, p. 1 17. 



{o;) \'ar. STELLiFER, var. nov. 



(/;) I'Lir. FAVOSUS, J]liitelegge. 



1907. Clathria favosa, Whitelegge, Austr. Mus. Mem., iv., 

 10, 1907, p. 498. 



General Diagnosis. — Sponge, in the different varieties, 

 ramose, Jamelliform or sub-massive. OsciiJa absent? 

 Dermal membrane strongly developed, appearing in the 

 dry sponge as a ivhitish pellicle or incrustation. Texture, 

 as revealed by the removal of the dermal covering, 

 rather loose and porous. The moderately stout fibre 

 forms a rather ivide-meshed reticulation. The main fibres 

 contain a dense spicular core, the connecting fibres, zvith 

 rare exception, are devoid of axial spicides. Smooth styli 

 are extremely abundant in the ground tissues. Acan- 

 thostyles occur not only as more or less deeply imbedded 

 echi)iating spicules, but also scattered within and betiveen 

 the fibres. They are more abundant on the outer ex- 

 tremcties of the fibres than elsewhere. The dermal skele- 

 ton is precisely of the same type as in the preceding 

 species. Megascleres : — In addition to acanthostyles 

 there are three kinds of stylote spicules, principal, aux- 

 iliary, and special dermal, occurring in the same relations 

 as in the preceding species. A certain proportion of the 

 last-mentioned exhibit a minute basal spination. (/.) The 

 principal styli are the stoutest spicides; they are, for the 

 most part, slightly curved; they vary in maximum size in 

 the different knoivn varieties from about 200 x 6 yi to 

 about 300 X 13 n. (n.) The acanthostyles are distin- 

 guished by the absence or marked reduction of spines over 

 a considerable portion of their basal moiety. {Hi.) The 

 auxiliary styli are straight or flexed, and are always 

 longer and slenderer than the principal, (iv.) The special 

 dermal styli are usually curved and slightly sub-fusiform; 

 The greatest curvature is in the basal half of their length; 

 in size they are rarely above ijo-150 x 4-5 ji. Micro- 

 scleres : — These are of three kinds: — (/.) Larger palmate 

 isochelcE, 15-20 n long: (ii.) smaller palmate isochelce of 

 ■ivhich a certain proportion are contort, j-ii \i long; (Hi.) 

 hair-like loxa of indefinite length, frequently passing into 

 amorphous forms, occurring both singly and in bundles. 



