88 STUDIES ON AUSTRALIAN MOLLUSCA, 



Sirius, gen.nov. 

 (Plate iii., fig. 8.) 



A genus of the Trichotropidce, differing by a turbinate instead 

 of conical shape, thin, without (as far as my information goes) 

 the characteristic epidermis of the type. Especially is it dis- 

 tinguished by a concave, expanded pillar, bi^oadening anteriorly 

 to an abrupt termination, and failing to reach the siphonal notch. 

 There is considerable similarity between Crossea and Sirius in 

 general shape and in the features of the base. 



Type Raidinia badia, Tenison-Woods. 



The type of my new genus was specifically described by 

 Tenison-Woods in these Proceedings (Vol. ii. 1876, p. 264), 

 and discussed at some length. His reference of a living species 

 to the genus Rmdinia, Mayer, created for a European Miocene 

 fossii has received the attention of subsequent textbooks. The 

 arguments advanced by Woods fail to convince me. I can trace 

 no sequence of family or genus between R. alligata and Sirius 

 badins. The salient character of the fossil is a sharp transverse 

 median fold on the columella; to this the broad, smooth columella 

 of Sirius badius presents no counterpart. In support of this 

 statement a figure of the Australian species (fig 8) is now 

 submitted for contrast with that of R. alligata, Deshayes (Journ. 

 de Conch, xii. 1864, pi. ix. fig. 8). 



As far as literature, in the absence of specimens, enables a 

 judgment to be formed, I am in accord with Prof. Tate (Proc. 

 Roy. Soc. N.S.W., xxviii., 1893 [1894], p. 182) in considering 

 the genus Raulima indistinguishable from the prior Isapis, H. 

 &■ A. Adams. 



Mr. Brazier informs me that the locality quoted by Woods is 

 erroneous, and that the specimen he furnished to that author 

 was procured in 1874 from sand and shingle at the entrance to 

 the Crookhaven River, Shoalhaven, N.S. Wales. I have seen the 

 species from Port Stephens, and have taken it dead in sand in a 

 cleft in the cliffs a mile south of the South Head Lighthouse; and 

 the example now figured from Balmoral Beach, Middle Harbour, 

 The original of my figure is 5 mm. in length. 



