55 



Tlie genus Gabhia was founded on an erroneous interpreta- 

 tion of tlie characters of a freshwater shell from New South 

 Wales. "Shell like Amnicola; operculum, paucispi^'al and 

 calcareous." " The figure of the unique species G. australis, 

 Tryon, Am. Journ. Conch., 1865, p. 220, t. 22, f. 7, reminds us 

 of Bithinia rather than any other genus, for in it the operculum 

 is represented as decidedly concentric, although said to be 

 paucispiral in the description" (Stimpson, on the Hydrobiinae, 

 p. 56). 



Later, Mr. Brazier described a shell from New South Wales 

 as Bithinia hyalina. An examination of typical specimens 

 proves the correctness of the generic position assigned, but a 

 comparison with the figure of Gahbia australis leaves no doubt 

 as to the specific identity of the two. The shell has, therefore, 

 been catalogued *by Messrs. Tate and Brazier as Bithinia 

 australis, Tryon, sp. ; consequently a new name must be given 

 to the B. australis of Mr. Smith, and I have much pleasure in 

 proposing that of Smith ii, after its original describer. 



Neritina crepidularia, Lamarck. 

 Bef.—Beeve, Icon. Con., t. 8, f. 38. 

 liah. — Port Essington (Capt. Wickham and J. B. Jukes). 



Corbicula ovalina, Deshayes. 



Bef. — Broc. Zool. Soc, 1854, p. 343 ; Smith, Broc. Lin. Soc, 

 1882, p. 299, t. 7, figs. 24-25. 



£[ab. — Port Essington. Adelaide Eiver (R.T.), a doubtful 

 identification. 



Corbicula Deshayesii, E. B. Smith. 

 Bef.—Op. cit., p. 303, t. 7, figs. 28-29. 

 BLab. — Victoria Eiver and Port Essington. 



Unia Stuartii, Adams and Angas. 



Ref—Broc. Zool. Soc, 1863, p. 417 (Alasmodon) ; Beeve, 

 Icon. Con., t. 54, f. 279 (Anodon). 



Hab. — Newcastle AVaters (Stuart Exped.) ; also in extra- 

 tropical Central Australia. 



Remarks. — I do not know why this shell was placed under 

 Alasmodon. In all stages of growth all the teeth are 

 developed, all are laminar, elongated, and slightly crenulated on 

 the margin ; anterior 2.1, posterior 1.2. A large example from 

 Newcastle "Waters has the following dimensions : — Length, 

 107 ; breadth, 52 ; thickness, 30 ; anterior side, 28 ; posterior 

 side, 79 millimetres. 



