226 -ENDEAVOUR" SCIENTIFIC RESULTS. 



No chelae have been observed, but specimens from which the 

 sarcode has not been removed are needed in order to enable one 

 to say positively that they are absent. 



Loc. — Southern coast of Australia {"Endea\'our"). 



It is necessary to point out that, in this species, the occur- 

 rence of spicules intermediate in form between the principal 

 and accessory spicules, is extremely rare — so rare, indeed, 

 that in some sections I have failed to observe them. I'he fact 

 of their presence, however, in this species and in C. nihcns, 

 is important, since it not only shows that these spicules are 

 not peculiar to the species of the C. spicata group [vide 

 p. 214), but also suggests that their occurrence may be more 

 widespread than previous descriptions of Chtihria species 

 would lead one to suppose. 



Clathria transiens, sp. nov. 



(Plate xxxiii., figs, i, 2, 3; Plate xxxiv., fig. 2; and 



figs. 47-48«)- 



Sponge stipitatc, ramose or suh-lobate ; branches free 

 or inler-uniting, often more or less restricted to one 

 plane, distinguishable into several orders. Surface 

 warty. Dermal membrane exceedingly thin or apparently 

 absent. Surface with closely scattered small sub-dermal 

 pores. Main skeleton a regular sub-rectangular reticula- 

 tion of moderately stout fibres. Main fibres with a dis- 

 crete, somexvhat paucispicidar slightly plumose core of 

 relatively large {principal) styli ivhich at the extremity of 

 the fibre form a spongin-free tuft; transverse fibres of a 

 spicule's length, usually with one or tivo axial spicules. 

 Echinating accessory styli, fairly abundant. Megascleres. 

 — (i.) Smooth, curved, sub-conical principal styli; maxi- 

 mum size variable, say at least joo x it \i ; (ii.) straight 

 conical styli with smooth or [more usually) slightly 

 roughened surface, in size rarely more than 80-go x 

 4-5 P' ("^O smooth, typically straight, auxiliary tylostyli ; 

 maximum size varying from about 280 x j to j6o x 6 ji. 

 Micro sclere s : — (/.) Palmate isochelce, sometimes rare or 

 absent, 14-26 ]i long; {ii.) geniculate toxa with straight 

 or recurved arms, varying in waxinium length from about 

 I JO to ijo }t, and in )naximum dia)ncter from i to j p. 



Introductory Remarks. — The four specimens which I assign 

 to this species differ considerably in general habit of growth 

 and also in the sizes of their spicules ; but in regard to the 

 conformation of the skeleton and the forms of their spicules, 

 they are practically identical. Consequently, whilst there can 



