REVISION OF FRESHWATER SPONGES OF SPONGILLIDAE 97 



Apparently restricted to the Australasian region, well dispersed 

 throughout Australia, and insufficiently known from New Zealand. 



Discussion. — The peculiar structure and often greatly varying 

 length of the gemmoscleres, so typical for this genus, created initial 

 difficulties in the assessment of its generic status by all previous 

 workers. These were furthermore increased by the absence of sufficient 

 data on all Australian sponges prior to a recent comprehensive re- 

 vision (Racek, MS.). The unequal development of gemmosclere 

 rotules, discernible at a varying degree in all Australian species, 

 caused Lendenfeld (1887) and Weltner (1895) to place some species 

 within the genus Tubella Carter, whereas others were recorded under 

 Ephydatia and Aleyenia, respectively. 



The erection of a new genus became necessary to demonstrate the 

 conspicuous differences of this typically Australasian group of species 

 from other spongillid genera. Although the writer intended to introduce 

 this new genus in his forthcoming revision of all Australian Spongil- 

 lidae, the scope of the present work made it imperative to incorporate 

 the genus Heterorotula mto this attempt of a worldwide revision. 

 However, since a number of recently found Australian species are not 

 represented in Penney's original collections for this study, only the 

 well-established species of this genus can here be considered. 



Heterorotula is more closely related to Ephydatia than to any other 

 genus, but it occurs in Australia side by side with the latter without 

 displaying any signs of hybridization. H. capewelli, H. multidentata, 

 and H. multiformis are by now well-known representatives of this 

 genus. H. kakahuensis from New Zealand is insufficiently described, 

 and gemmules are absent from our material available. Its generic 

 status, therefore, cannot as yet be reliably resolved. Until further 

 material can be studied, it seems advisable to leave the New Zealand 

 species provisionally within this genus. 



Heterorotula capewelli (Bowerbank, 1863) 



Plate 8, figures 1, 5, 8 



Spongilla capewelli Bowerbank, 1863, p. 447. 



Ephydatia capewelli Gray, 1867, p. 550. — Weltner, 1895, p. 122; 1910, p. 137. — 



Gee, 1931d, p. 25; 1931e, p. 35. 

 Meyenia capewelli Carter, 1881a, p. 93. — Potts, 1887, p. 158. — Penney, 1960, p. 47. 



Material. — Slides of type (BM) and syntype (N. Gist Gee and 

 ZMB) ; material and slides from western New South Wales, Australia 

 (Racek) . 



Description. — Sponge rather massive and bulbous; surface dis- 

 tinctly lobular, with high and rounded irregular ridges separated from 

 each other by comparatively deep clefts; oscula few in number but 



