320 On Sponges from South Australia. 



they must form part of the foreign microscopic objects of a 

 genuine Psammonematous sponge, for which the existence of 

 a family Pseudohircinicla is therefore no longer necessary. 



This I have seen for some time past, and my attention was 

 first called to it by finding two species of caulescent Chalinida, 

 in which the fibre not only contained the spicules of the 

 species entire, but also, in addition, sand-grains and other 

 microscopic foreign objects ; hence it may be remembered 

 that, in the ' Annals ' of 1882 (vol. ix. p. 280), I described 

 these two species under the names respectively of " Chalina 

 digitata, var. arenosa" and " Gavochalina diqitata, var. are- 

 nosa" in a new family named " Pseudochalinida," which I 

 proposed to add to the order Rhaphidonemata. 



And now it seems to me desirable that a similar transfer 

 should be made to the order Echinonemata. 



At first I thought, from the abundance of foreign material 

 and great thickness of the keratose envelope in the fibre of 

 the skeletal specimens of this kind in the British Museum, 

 that the echinating spicules had been appropriated by the 

 Psammonematous sponge, and so made a group to receive 

 them under the name of " Armatohircinina " (loc. cit.) ; but 

 having had to examine a spirit-preserved specimen as well as 

 a dried one, taken respectively from their natural habitat by 

 Mr. Wilson, it seems to me much more reasonable to infer, 

 from the following facts, that the Echinonematous rather than 

 the Psammonematous fibre took in the foreign objects. 



Thus in the species Echinonema anchoratum ('Annals,' 1881, 

 vol. vii. p. 379) the spiculation consists of an acuate skeletal, 

 a spined clavate echinating, and an equianchorate flesh 

 spicule, each of which has its fixed position in the sponge ; 

 that is, the acuate spicule forms the core of the fibre ; the 

 echinating spicule is attached to the outside or surface of the 

 fibre, and the equianchorate is restricted to the surrounding 

 sarcode, which is precisely the case in the " Armatohircinina." 



Now on examining the species in Mr. Wilson's collection 

 to which I have alluded — which, from its large size, handsome 

 tiabellate growth, firm consistence, transparent, colourless, 

 <-lass-like keratose fibre, and greyish-white colour generally, 

 together with the presence of several dry specimens of the 

 same sponge in the British Museum (under the no. 128), 

 which came from the southern coast of Australia, indicating 

 that it is not only a striking object but prevailing form there, 

 1 shall name "WHsoneila australiensis" — it is evident that a 

 similar spiculation, in which the spicules are entire, with the 

 same arrangement, exists in this species as in Echinonema 

 anchorata; hence, in accordance with what I have above 

 stated, Wilsonella australiensis will be more particularly 



