FEESHWATER SHELLS OF ATJSTEALTA. 279 



Var. = Aplexa Adamsiana, Canefri, Viag. Magenta, p. 103, pi. iii. fig. 3. 



Physa proteus (part.), Sowerby, I. c. fig. 43c. 



Sab. New South Wales. 



This species, judging from the specimens in the Museum which 

 I consider belong to it, is very A^ariable. The typical forco has 

 rather a short spire ; but this in certain examples is much pro- 

 duced, so that the length above the aperture eq^uals half the shell. 



The Museum specimens are from Cook's Eiver near Sydney, 

 from Denbigh, Liverpool, and Parramatta. New Zealaud is given 

 by Sowerby, and is evidentl}- incorrect. 



The large form named Adamsiana hy Canefri, of which there are 

 several specimens in the Museum, does not, I think, exhibit any 

 constant specific differences. It certainly presents a very diffe- 

 rent appearance to the normal gihhosa, lacking the shouldering 

 or gibbosity of the last whorl, and exhibiting a comparatively 

 elougated spire ; still, in a large series, such as that before me, 

 there are many intermediate forms ; so that the conspecific rela- 

 tionship is apparent, and it becomes impossible to draw a line of 

 limitation. 



56. Physa pectoeosa, Conrad. (Plate YI. fig. 11.) 



Physa pectorosa, Conrad, Proc. Acad. JSat. Sci. Philad. 1850, vol. v. 



p. 11 ; id. American Journ. Conch, ii. p. 81, pl.i. fig. 6. 

 Var. = Physa pinguis, Sowerby, Con. Icon. fig. 93 a-b. 



Sal. Bogan E-iver {Conrad) ; Balonne Eiver {McQillivray); 

 South Australia {Sowerby). 



The figure of this species in the ' American Journal ' does not 

 show the ventricosity of the penultimate whorl at all satisfactorily. 

 The double fold on the columella is not peculiar to this species ; 

 for the same character, by no means a constant one, is met with 

 in some specimens of P. gibiosa, P. proteus, and other species. 

 P. pinguis difiers from the typical form in having a shorter spire, 

 which is subject to much variation in this genus. 



57. Phtsa austealiana, Conrad. (Plate VI. fig. 12, after 

 Conrad.) 



Physa australiana, Conrad, Proc. Acad. Nat. Sci. Philad. 1850, vol. v. 



p. 81 ; id. American Journ. Conch, ii. p. 81, pi. i. fig. 7- 

 " Elliptical, thin, diaphanous ; volutions 4 or 5, regularly con- 

 vex ; spire short ; epidermis amber-coloured ; columella with a 



