Sponges from South Australia. 41 



at all . Hence we have to deal here not with the " limited 

 acceptation " of the term " sponge," but with the products of 

 the sponge-animal in its most extended sense, although 

 at one time, as in the Carnosa, this may be almost 

 undistinguishable from glue when both are dried, at another, 

 as in the sponge of commerce (which is the most familiar 

 form), a resilient mass of horny thread-like tissue (that is the 

 skeletal structure of the sponge from wliicli the soft parts 

 have been extracted by putrefaction and edulcoration), and in 

 a third, as in the Lithistina, so compact and stone-like that 

 it yields to nothing but a knife or hammer. 



So much for the order then ; let us now turn our attention 

 to the families respectively. 



Fam. 1. Renierida. 



Char. Spicules more or less arranged in a fibrous form ; 

 structure yielding to pressure, like crumb of bread. 



To this family my experience of the last ten years, viz. 

 since my " Notes Introductory to the Study and Classification 

 of the Spongida " were published in 1875 (' Annals,' ser. 4, 

 vol. xvi. p. 177 et seq.), has not enabled me to add much, and 

 I have very little to alter. Many new species I have described ; 

 but they must be sought for in the pages of this periodical, 

 which I have not time now to specify. 



Phlceodictyonina (new group). 



I would, however, observe that, having found several 

 species more or less presenting the characters of Oceanaria, 

 ]>lorma.n= Desmacidon Jeffrey sii.^ Bk., I have put them 

 together under the above name, and would place this new 

 group immediately after no. 4, viz. " Crassa." More I need 

 not state of it here, as the whole will be found in the ' Annals ' 

 for 1882 (vol. x. p. 117 et seq.)^ and an additional species in 

 those of 1883 (vol. xii. p. 326 et seq.). 



To the mode of circulation in the Phloeodictyons, in which 

 no vents have been discovered, I shall have to return here- 

 after when describing some of Mr. Wilson's specimens of 

 Polymastia from Port Phillip Heads, in which, by analogy, 

 the position of these vents seems to be indicated. 



I have also added a few remarks as well as descriptions of 

 new species to group no. 8, viz. " Esperina " (' Annals,' 1882, 

 vol. ix. pp. 288-301 ; ib. 1880, vol. vi. p. 49, pi. v. fig. 20 ; 

 ih. 1874, among the " Deep-sea Sponges dredged by H.M.S. 



