494« Land and Freshwater Shells 



lines; volutions 4; spire short and acute; aperture ovate; 

 outer lip thin; inner lip reflected, forming a small hollow 

 behind it. 



This remarkable shell is only found in one pond in our 

 neighbourhood ; and the reversed variety is of rare occur- 

 rence. It differs from our specimens of L. pereger in being 

 thicker and stronger; is of a darker colour, and only half 

 the size : it is certainly very like some of the numerous 

 varieties of this shell, yet most of our scientific friends agree 

 with us in considering it specifically distinct. The raised lines 

 on the body whorl are very variable : in some specimens they 

 are nearly obliterated; but in very few instances are they 

 wholly wanting. Mr. G. B. Sowerby, in his Genera of Recent 

 and Fossil Shells, united Physa, Myxas, and Aplexa to the 

 genus Limnea. He says, " the only describable difference in 

 the shells, except mere specific differences, consists in the 

 Aplexa and Physa being heterostrophe shells, while the Lim- 

 nea and Myxas are dextral. The reversed Limnea found 

 at Scarborough will certainly prove the correctness of Mr. 

 Sowerby's views. 



Scarborough, July 30. 1834. 



Art. VII. A List of some Land and Freshtvater Species of Shells 

 tvhich have been found in the Neighbourhood of Henley on 

 Thames, By H. E. Strickland, Esq. 



I SEND you a list of land and freshwater shells which I 

 found, some years ago, in the neighbourhood of Henley on 

 Thames, a district which furnishes a greater number of spe- 

 cies than any other with which I am acquainted. This is 

 doubtless owing to the diversity of hills and valleys, wood 

 and water, which adorn that charming neighbourhood, and 

 supply to each species an appropriate habitat. I have thought 

 it best, in the case of the more rare species, to state exactly 

 the locality or situation where each occurs ; as, without this 

 knowledge, a conchologist might search for them a long time 

 without success : v r mean very rare ; r, rare ; f, frequent ; 

 c, common. 



Mollusca Gasteropoda Pulmonifera Terricola, — Cyclos- 

 toma elegans, beech woods,y^ Carocolla lapicida, adhering 

 to beech trees, yi Helix aspersa, c; nemoralis, c\ hortensis, 

 /; arbustorum, moist plantations, r ; ericet6rum, dry chalky 

 banks, c ; virgata,y ; caperata,^; rufescens, c ; hispida Drap, 

 (not of Montagu), c, cantiana (Carthusiana Drap.), hedges 

 and plantations, c ; fusca, Fawley Woods, v r ; alliaria, damp 



