HELIX. 891 



of an uniform whitish colour, except the ultimate whirl, 

 which forms a brown spot in the center ; the upper surface 

 is very flat, and bordered bj a sharp keel, below which the 

 base is remarkably gibbous and umbilicated ; it has four or 

 five whirls, which are prettily striated transversely. Petiver 

 has not unaptly called it * a small Trochus reverst, having 

 its head flat and belly raised.' I have received it from the 

 West Indies. The shell which Chemnitz has figured for H. 

 albella does not accord well either with the description of 

 the Linngean H. albella or Muller's H. explanata, and is 

 most probably a distinct species. Linnaeus has erroneously 

 quoted Gualter, t. 3. f. Q, which is H. rotundata. 



ALBINA. 10. Shell umbilicated, keeled, with the 

 spire flattened, and the base gibbous ; aper- 

 ture quadrangular. 



Helix albina. Midler Verm. ii. p. 25. Gmelin, p. 36 15. 

 Lister Conch, t. 86. f. 86. ? 



Inhabits 



Shell about three lines in diameter, with three whirls, and white 

 without any spots ; the body-whirl has an acute keel, and 

 Muller says it resembles H. albella, but may be distin- 

 guished by a tooth in the middle of the whirl opposite the 

 aperture. 



ROTUNDATA. 11. Shell umbiHcated, slightly keeled, 

 with six strongly striated whirls ; spire de- 

 pressed, and the base convex. 



Helix rotundata. Muller Verm. ii. p. 29. Gmelin, p. 

 3633. 



Helix radiata. Da Costa Brit. Conch, p. 57. t. 4. f. 15 

 and 16. Montagu Test. p. 432. t. 24. f. 3. Maton and 

 Racket f in Lin. Trails, viii. p. J 99. Dorset Cat. p. 54. 

 t. 20. f. 15 and 16. 



Helix, No. 275. Schroeter Eiiil. ii. p. 256. 



Le Bouton. Geoffroy, p. 39, No. 9. t. 2. 



Lister Conch, t. 1058. f. 11 A. Petiver Gaz. t. 31. f. 5. 

 Gualter, t. 3. f. Q. Jrgenvilte Zoom. t. 9. f. 10. Schroe- 

 ter Erdconch. t. 2. f. 25. 

 Inhabits Denmark and Norway; under the bark of decayed 



trees, and among moss in woods. Midler. France. Geof- 



froy. England. Da Costa, S^r. 

 Shell about a quarter of an inch in diameter, of a pale dull 



brown colour, prettily rayed or rather tessellated with chest- 



