FRESHWATER AND LAND SHELLS. 87 



Diam. -3, Length -9 of an inch. 



Remarks A delicate little species, of which I received but a sin- 

 gle specimen, and this not entirely perfect in the mouth. The spots 

 are quadrate, and arranged in a double series on the four lower whorls. 



Helix Mitchelliana. Plate XXIII. fig. 71. 



Testa supern^ obtuso-conicd, infern^ inflatd, longitudinaliter et subtiliter striata, corned, dia- 

 phand, imperforatd ; anfractibus quinis; aperturd subrotundatd ; labro rejlexo; columelld lavi. 



Shell above obtusely conical, below inflated, longitudinally and finely striate ; horn- 

 colour, transparent, imperforate ; whorls five ; aperture nearly round ; outer lip reflesed ; 

 columella smooth. 



Hab. Ohio. J. K. Mitchell, M. D. 



My Cabinet. 

 Diam. •7, Length "4 of an inch. 



Remarhs.-^l am indebted to Dr Mitchell for this shell, which was 

 sent to him by a friend from Ohio. It is rather larger than the H. clausa 

 (Say) and H. jejuna (Say), but in form resembles them. It may be dis- 

 tinguished from the latter in not being perforate, and from the former 

 in having a sharper lip. In its striae it is distinct from both, in having 

 them larger and much better defined. 



Helix Vancouverensis. Plate XXIII. fig. 72. 



Testd plano-convexd, inferni planulatd, nitidd, longitudinaliter striatd, corned, lath umbili- 

 catd ; anfractibus quinis, rotundatis; apertura subrotundata ; labro infernh subrejlexo, supernh 

 depresso ; columelld brevi, callosd. 



Shell plano-convex, below flattened, shining, longitudinally striate, horn-colour, wide- 

 ly umbilicate ; whorls five, rounded ; aperture roundish ; outer lip below somewhat re- 

 flexed, above depressed ; columella short, callous. 



