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•ENDEAVOUR" SCIENTIFIC EESULTS. 



Rhaphidophlus paucispinus, LendenfeJd. 



{a) Typical F()rm. 



(Plate XXV., fig. I ; Plate xx\i., fig. i ; and figs. 36,' 36a.) 



tS88. ThaJassodenclron paucispina, Lendenfeld, Austr. Mus. 

 Cat. Sponges, 1888, p. 224. 



Thalassodendron rubcns, var. dura (pars), Lendenfeld, 

 Log. cit., p. 224. 



Thalassodendron nihctis, ^ ar. lamella (pars), Lenden- 

 feld, Loc. cit., p. 224, pi. vii. 



jgoi. llialassodendron nibens (pars), Whitelegge, Rec. 

 Austr. Mus., iv., 2, 1901, p. 87. 



[T. nibens, var. dura; T. rubens, var. lanicllosa ; T. 

 paucispina), Whitelegge, Loc. cit., p. 87. 



(b) Var. MuLTiPORA, Whitelegge. 



(Plate XXV., fig. 2.) 



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



10, 1907, p. 496, pi. Xlv., fig. 2T,. 



General Diagnosis. — Sponge variable in habit, uni- 

 flabellar, midtijlabellar or ramose; usually attached by a 

 ■more or less extended disc-like foot, %vitli or ivithoiit the 

 intervention of a stalk. In all cases the form assumed is 

 the outcome of a more or less distinctly expressed ten- 

 dency to the restriction of growth to one plane. No osctda. 

 Dermal membrane strongly developed, appearing in the 

 dry sponge as a white pellicle or incrustation. The sur- 

 face exposed by the removal of the dermal skin is closely 

 dotted with pinhole-like punctures. The main skele- 

 ton is a fairly regular, small-meshed reticulation of stout 

 fibres; the main fibres contain a semi-diffuse core, the 

 connecting fibres are short and invariably enclose one or 

 a few spicules. The dermal skeleton is a xvell-defined 

 reticulation of lines of croivded styli of ttvo sizes, the 

 smaller standing vertically, the larger lying horizontally 

 beneath these and supporting them. Megascleres : — (/) 

 Stouter, usually slightly curved, (principal) styli, chiefly 

 confined to the fibres, varying in maximum size in the 

 different forms from 260 x 9 to J50 x 16 y,; [ii.) conical 

 tapering acanthostyli, most densely spined on the basal 

 end, occurring sparsely as echinating spicules and scat- 

 tered in the ground-substance ; length go-ioo p; {Hi.) 

 slenderer, usually straight (auxiliary) styli (or subtylo- 

 styli) of the same length as, or slightly shorter than the 

 principal, occurring horizontally in the dermal membrane 



