71 



NOTES ON BYTHINELLA, Etc. 



By the Eev. J. E. Tenison- Woods, F.G.S., F.L.S., Hon. 

 CoE. Mem. E. Soc. Tas., and President of the Linn. 

 Soc. N. S. Wales. 



Last year I reviewed in the proceedings of this Society the 

 synonomy of the genus BytJmiella as far as it is represented 

 by the small freshwater shells of our streams. Since then I 

 have had my attention drawn by Prof. Tate to a species 

 described by Messrs. Quoy and Gaimard, which from the 

 figures and diagnosis I make no doubt belong to the genus, 

 and probably a subsequently described species ; have also had 

 an opportunity of seeing Mr. J. Brazier's type specimens of 

 his Amnicola Petterdiana, in which I can see no differences to 

 distinguish it from the shell already described. I was not 

 able to examine this type specimen before, as Mr. Brazier had 

 left Sydney, and his collection was packed away. In conse- 

 quence of this I was obliged to omit any reference to the 

 species in my last paper. 



The diagnosis of Messrs. Quoy and Gaimard is as follows: 

 Paludina nigra. Q. and G. Voyage de I'Australe, vol. 3, p. 

 174, plate 58, figs. 9, 12. P. t. minima, ovato-turrita, nigra; 

 anfractihiis quaternis obliguis, convexis, sj>ira obtusa, apertura, 

 suhcirculari, jjrominente. (Shell minute, ovately turretted, 

 black, whorls four, oblique, convex, spire obtuse, aperture 

 subcircular, prominent). The last whorl equalling all the 

 others. Umbilicus scarcely visible. Black when alive, 

 brownish by dessicatiou. Foot oval, muzzle prominent, 

 cordiform, extended beyond the foot, tentacles long, obtuse, 

 eyes at the base, animal all black except the underside of the 

 foot, which is whitish. Operculum membranaceous. Inhabits 

 the small freshwater streams of D'Entrecasteaux Channel. 

 They add that it cannot be the young of any species, as they 

 found it in such numbers and all of the same size. 



I make no doubt that from both the habitat and description, 

 that this is our common Bythinella, which has therefore the 

 following synonomy : 



Bythinella nigra. Quoy and Gaimard, loc. cit. Paludes- 

 trina Wisemaniana ; Brazier, Proc. Zool. Soc. Lond. 1871, p. 



