502 Transactions of the Society. 



each prism is traversed by a tube, represents the so-called " pore 

 tubulation." 



The vesication of Aphrosina informis forcibly recalls to mind 

 that of j¥]fhalium septicum, -whose active state is so like Amoeba ; 

 and whose form and appearance sometimes, are almost identical with 

 LieherJciihnia Wagneri* 



SjpicuJation of an unknoivn Sponge. 



On the surface of the foregoing species of Aphrosina informis 

 are plentifully strewn the spicular remains of an unknown sponge 

 remarkable for the size of the larger bihamates, which almost equal 

 in length the skeleton - spicule, and on this account it seems 

 desirable to record the fact, together mth an illustration of each 

 spicule drawn to the same scale, viz. ^^ inch to ^oVxr inch, in order 

 that their relative sizes may be at once realized. 



Skeleton - spicule acuate, slightly fusiform, and sometimes 

 spinulate (Plate XVIIa, Fig. 12, a); large flesh-spicule bihamate, 

 simple, smooth, showing plainly the central canal (Fig. 12, h) ; 

 small flesh-spicule equianchorate, navicular, alae or flukes inflected 

 (Fig. 12, c). 



Skeleton-spicules in successive bundles, indicating a fibrous 

 arrangement, among which the bihamates of various sizes are 

 plentifully scattered, together with a few equianchorates. The 

 spiculation somewhat resembles that of Esperia villosa.^ 



* Clap, et Lach., ' Etudes Infusor.,' vol. i. pi. 23. 



t ' Annals,' 1874, vol. xiv. pi. xiii. fig. 13, &c. (' Porcupine ' dredgings). 



