544 REVISION OF THE AXINELLID.*:, ii., 



author to the genus Spongosnrites, under the erroneous impression 

 that the inicroscleres present — which are exceptionally slender 

 trichite-sheaves, peculiar in being often more or less fusiform in 

 shape — were microxea. Even had the microscleres been as 

 stated, however, it is not to Sponyosorites that the species would 

 have required to be assigned, but probably to Cerafopsis. 

 Hitherto, all species with a plumose or with an axially-condensed 

 type of skeleton, and with trichodragmata only as microscleres, 

 have been included in the single genus Thrinacophora, but I now 

 propose to regard them as representative of several distinct 

 genera. 



Dragmaxia variabilis Whitelegge. 

 (PL xxxviii., figs.l, 2, 3.) 



1907. SponyosoritPS variabUis Whitelegge(60), p. 5 13, PI. xlvi., 

 fig. 45. 



Diaynosifi. — Thinly lamellar, varying from ilabelliform to 

 caliculate. The lamina alternately denser and less dense along 

 lines running towards the margin, and thus presenting an ap- 

 pearance as of venation, with corresponding faint ridges and 

 grooves on the surface. The surface otherwise even. Dermal 

 membrane distinct, aspiculous. Oscula inconspicuous. Skeleton 

 consisting of dense spicule-axes corresponding in position with 

 the "veins," and of stout plumose fibres running outwards there- 

 from to the surface. Spongin rather scanty. Megascleres: styli 

 only, not quite perfectly differentiated into two kinds ; those 

 forming the fibres are shorter, stouter, and more curved, attaining 

 a maximum size of about 900 by 33/x; the others, which are 

 relatively few and occur only interstitially, occasionally surpass 

 1 300 or 1 400/A in length and are not more than 1 8/x in diameter. 

 The trichodragmata vary from about 100 to 200/x in length and 

 up to 5/1 in stoutness; singly scattered trichites, similar to those 

 forming the dragmata, also occur. 



Loc.—Ofi Crookhaven River, N.S.W. ("Thetis."). 



Externa/ features. — The original specimen was rudely cup- 

 shaped or, rather, compi'essed funnel-shaped, with a few laterally 



