72 



expanded, acute, fragile ; columella arched, plait inconspicuous. 

 Long. 15. Lat. 9. Aperture 11 mill. 



Habitat, Creek near Launceston. While in habit this shell 

 much resembles the two preceding it is larger and of shining 

 white or silvery lustre. I also think that there are signs of a 

 band circling the shell formed by two parallel lines. 



PHYSA. 



Genus Physa Drapamaud. Hist. Nat. des Moll. d;c., de la 

 France, 1805. 



Testa fluviatilis, cornea, tennis, spiralis, sinistrorsa, plerutnque 



ovato-aciominata ; labio externa acuto, siniplici ; labio interna 



cxpanso, cum coliomella continua ; columella contorta, uniplicata, 

 (J2)erculum nullum. 



Shell fluviatile, horny, thin, spiral, sinistral, generally ovate, 

 acuminated ; outer lip expanded, continuous with the colu- 

 mella ; columella tortuous, singly-plaited. No operculum. 



The Physffi may be considered sinistral or reversed 

 Limneadse. They are most numerous in warm countries, 

 but are found in Britain. The usual species are found in 

 Europe and South Africa, and they prefer running streams. 



1. P. APERTA. P. testa 2)arva, brevi, ovata, injlata, epidermide 

 olivaceo-fusca induta ; spira brevissima, anfractibus duobus, ultima 

 inflato, superne sub-gibboso ; apertura magna, lata, intus sub 

 coerulea, columella contorta, plica promimda. 



Shell small, short, ovate, inflated, covered with an olive 

 brown epidermis ; spire very short, with two whorls, last 

 whorl inflated, rather gibbous above : aperture large, broad, 

 bluish within, columella tortuous, fold rather prominent. 

 Sowerby, in Reeve's Icon. Plate xi., figs 88, a b. 



Habitat, creeks between Hamilton and New Norfolk, 

 Tasmania. 



2. P. ET5URNEA. P. tcsta gracUi, obliqua, suhfusiformi, polita, 

 alba, fulvescenti, semi^yellucida ; spira acuminata, quam apertura 

 longiori ; anfractibus obliquis, declivibus, attenuatis ; apertura brevius- 

 cula, subaurifurmi, intus fusco riibescenti ; columella contorta, alba 

 medAo interdum incrassata. 



Shell slender, oblique, rather fusiform, polished white 

 fawn, seiuipellucid ; spire acuminated, longer than the aper- 

 ture, whorls oblique, sloped, attenuated ; rather short, sub- 

 auriform, reddish brown within, columella tortuous, white, 

 sometimes thickened in the middle. 



Sowerby, in Reeve's Icon, PI. xi., figs 89 a. b. 



Habitat, creeks near Launceston. 



3. Physa mamjllata. P. testa elongata, fusca, antice suhex- 

 pansa ; splrA quam apertura breviuscula ; anfractibus aplcalihus 



