259 



Brard, p. 147. t. 6. f. ], 2.; Sowerby, Genera, f. 

 I . ; Jeffreys, Linn. Trans, xvi. ; Rossm. Icon. 

 ii. 14. t. 7. f. 113.; Turton, Man. ed. 1. 112. 

 f. 95. 



Helix cornea. Linn. S. N. 1243.; Mont. Test. 

 Brit. 449. 



Planorbis purpureus. Mutter, Verm. ii. 154. 



Junior, Planorbis similis. Mutter, Verm. 166. 



Helix nana. Penn. B. Z. t. 125. 



In muddy streams and ditches. 



Animal black. (Sturm, t. 40.) 



Shell an inch in diameter, thick, black, or of a rusty 

 brown colour, obliquely striate; volutions five, the outer 

 one rounded, with a deep umbilicus on the under or 

 front side, exposing three of the volutions ; upper sur- 

 face a little concave and whitish; aperture rather 

 oblique, rounded, as high as broad. 



The young shells are finely spirally striated. 



101. 2. PLANORBIS albus. White Coil Shell, (t. 8. 

 f. 97.) Shell thin, pellucid, white, concave, and 

 with the whorls equally convex on both sides, with 

 fine raised hispid spiral striae ; mouth roundish- 

 rhombic. 



Planorbis albus. Mutter, Verm. ii. 164. ; Leach, 

 Mollusc, p. 156. ; Jeffreys, Linn. Trans, xvi. 387. ; 

 Turt. Man. ed. 1. 114. f. 97. 



Planorbis hispidus. Drap. p. 43. t. 1 . f. 45 48. ; 

 Brard, p. 159. t. 6. f. 6, 7.; Lam. Moll. vi. 154. 



Helix alba. Mont. p. 459. t. 25. f. 7. 



spirorbis. Linn. S. N. i. 1244. ? 



Planorbis reticulatus. Risso ? 



Var. Planorbis glaber. Jeffreys, Linn. Trans, xvi.; 

 Potiez and Midland, Gall Moll i. 211. 



