HELIX. 907 



\ 

 Helix Cornu Arietis. Da Costa Brit. Conch, p. 60. t. 4. 



f. 13. 

 Planorbis Purpura. Muller Ferm. ii. p. 154. 

 Le Grand Planorbe. Geoffroy, p. 86. No. 1. t. 3. 

 Bonanni Rec. and Kirch. 3. f. 3l6, and Kirch. 312. Lis- 

 ter Anim. Jng. t.2. f. 26, and Couch, t. 137. f.41. Pe- 

 tiver Gaz. t. 92. f. 5. Gualter, t. 4. f. D D. Argen- 

 ville, t.27. f. 8, and Zoom. t. 8. f. 7- Seba, iii. t. 39. f. 

 17. Knorr, v. t. 22. f. 6. Geve, t. 3. f. 18 and 19. 

 Martini Berl. Mag. iv. t. 8. f. 17. 

 Junior. Shell smaller. 



Helix nana. Pennant Zool. iv. p. 134. t. 83. f. J 25. 

 Inhabits slow rivers and stagnant waters ; common throughout 



Europe. 

 Shell about an inch in diameter, and the aperture is about one- 

 third as broad; it is of a reddish brown, or frequently of a 

 horn-colour, with four rounded transversely wrinkled whirls, 

 coiled horizontally, and separated by a deep suture ; the up- 

 per side is strongly umbilicated, and more concave than the 

 lower. 



siMiLis. 48. Shell umbilicated on the upper side, 

 with four rounded striated whirls, and elevat- 

 ed dots on the stria?. 



Helix similis. Gmelin, p. 3625. 



Helix, No. 320. Schroeter Einl. ii. p. 269. 



Planorbis similis. Muller Verm. ii. p. 166. 



Martini Berl. Mag. iv. p. 265. t. 11. f. 64 B. 

 Inhabits ditches in Denmark, and about Berlin. Muller. 

 Shell three lines in diameter, and the diameter of the whirls is 



two lines ; Muller says it resembles at first sight a young shell 



of //. cornea, but is of a yellower colour, and under a glass 



the striae appear to be armed with minute elevated dots. 



spiRORBis. 49. Shell concave on both sides, with 

 six rounded whirls. 



Helix spirorbis. fAnnaius Sj/st. Nat. p. 1244. Schroeter 

 Fluss. p. 236. t. 5. f. 13, and Einl. ii. p. 138. Gmelin, 

 p. 3624. Montagu Test. p. 455. t. 25. f. 2. Ma ton and 

 Racket, in Lin. Trans, viii. p. ]{)]. J)(>rsef. Cat. p. 53. 

 t. 20. f. 1 7. 



Planorbis spirorbis. Muller Ferm. ii. p. l6l. 



Le petit Planorbe. Geofroi/, p. 87. No. 2. t. 3. 



