BY E. F. KALLMANN. 281 



Tkthya L^VIS. 



The sponge, which T identify as Tethya hcv^^^ is a common one 

 in the neighbourhood of Port Jackson, and is represented in tlie 

 Australian Museum by some dozens of examples. Tlie specimens 

 labelled as the types of Tethya corticata and Tetliya iiifiata, as 

 well as the fragments labelled with the same names from the 

 British Museum, are, as already stated, examples of it; and it is 

 represented (along with several examples of Tethyorrhaphis 

 l(fvis) among the specimens labelled as the types of Tethya hcvis. 

 There can be no doubt, also, that the species is identical with 

 the Tethya ingalli recorded from Port Jackson by Sollas(36); but 

 as proof is yet lacking of its strict identity with Bowerbank's 

 species of that name, the locality of which is Western Australia, 

 I propose to regard it as a variety thereof, and to designate it 

 D. ingalli var. Icp.vis. 



The sponge, which appears always to be more or less spherical 

 in shape, and to grow attached to the substratum by root-like 

 processes, is chiefly distinguished, so far as external features are 

 concerned, by the entire absence of any sign whatsoever of 

 surface- tessellation, and by the very small size of the oscula, — 

 the latter being, as a rule, at any rate in the case of pi-eserved 

 (and contracted) specimens, almost or quite invisible. The pores 

 are not discernible; and there is no perceptible minute reticu- 

 lation of the surface as in D. phillipensis. The surface is mam- 

 millated, the elevations varying in shape in different specimens, 

 or even in different parts of the same specimen, from low and 

 dome-like to verruciform; in most specimens, a certain proportion 

 of these elevations are provided apically with a thread-like pro- 

 cess, at the extremity of which a bud is often to be observed. 



The two previous accounts of the sponge are not quite full and 

 accurate concerning its spiculation, more especially in regard to 

 the megascleres. These spicules are imperfectly differentiated 

 into three kinds, the typical representatives of each of which are 

 distinguished not only by their form and size, but also by their 

 different situation in the sponge. The spicules of one kind are 

 chiefly or exclusively confined to the fibres and ahnost entirely 

 compose them; these attain a maximum length varying between 



