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•ENDEAVOUE" SCIENTIFIC RESULTS. 



impression that the fibres "which curve gracefully outwards 

 and terminate at the surface" are branches arising from the 

 stouter main fibres of the "axial plexus" (as for example in 

 Clathria arcuophora), whereas, as a matter of fact, they 



appear rather to be direct 

 continuations of those 

 fibres. The description 

 also errs in attempting to 

 fix precise limits to the 

 diameters of the axial, 

 superficial and transverse 

 fibres. 



The principal styli vary 

 in length from about 75 to 

 220 >i, and in diameter up 

 to 8 or (very rarely) 9 y ; 

 generally speaking, they 

 agree in form with those 

 of O. suhhispida but are 

 somewhat peculiar in the 

 fact that a considerable 

 proportion (usually of the 

 stouter individuals) are 

 wanting in the slight basal 

 swelling or knob charac- 

 teristic of the latter, and 

 thus have the basal ex- 

 tremity shaped somewhat 

 like the handle of an oar. 

 However, I find that this 

 peculiarity is also occa- 

 sionally exhibited, though 

 in a less marked degree, 

 by the spicules of O. suh- 

 hispida, and is therefore of 

 doubtful value as a dis- 

 tinctive character of the 

 variety. 



The auxiliary spicules are slender, usually curved or fiexuous 

 tylostyli which seldom exceed 200 |i in length, and appear to 

 be never more than i \i \n diameter ; the longest observed 

 measured 240/1. In O. subliispida also, it should be noted, 

 the auxiliaries are sometimes flexuous. 



The toxa are similar in form to, and (except for a slighter 

 stoutness) of the same dimensions, as those of O. suhhispida. 



Loc. — Coast of New South Wales, Illawarra (Austr. Mus. 

 Coll.). 



Fig. 55 — Ophlitaspongia suhhispida, 

 var. viviinalis. a Principal styli 

 (selected) showing in varying degree 

 the basal peculiarity, b Auxiliary 

 tylostyli. 



