160 LIMN^AD^. 



tion, even when marked, does not acutely project. The 

 month, likewise, which is still smaller in proportion to the 

 total breadth, is as high as it is broad, and is of a much 

 more rounded shape, not being angulated by a carina. Di- 

 ameter a quarter of an inch. 



Animal closely resembling the last. 



In local lists it is difficult, where both species do not 

 occur to separate this from the preceding. P. spirorbis, 

 however, appears to be still more generally diffused, and 

 to have a wide distribution through most districts of the 

 three kingdoms. 



P. contortus, Linnaeus. 



Whorls closely coiled, narrow, high ; upper disk flattened, 

 lower one deeply excavated ; periphery rounded. 



Plate CXXVI. fig. 3. 



Helix contorta, Linn. Syst. Nat. ed. 12, p. 1244. — Donov. Brit. Shells, vol. iii. 



pi. 99. — Mont. Test. Brit. p. 457; Suppl. pi. 25, f. 6.— Maton 



and Rack. Trans. Linn. Soc. vol. viii. p. 191. — Rack. Dorset 



Catalog, p. 53, pi. 20, f. 11. — Turt. Conch. Diction, p. 48. — 



Dillw. Recent Shells, vol. ii. p. 908. — Wood, Index Testae. 



pi. 33, f. 52. 



Planorbis contortus, Muller, Verm. Hist. pt. ii. p. 1G2. — Fleming, Brit. Anim. 



p. 277. —Jeffreys, Trans. Linn. Soc. vol. xvi. p. 382. — 



Turt. Manual L. and F. W. Shells, p. 113 (ed. Gray, 



p. 270), f. 9G.— Macgil. Moll. Aberd. p. 118.— Brown, 



Illust. Conch. G. B. p. 33, pi. 14, f. 33, 34. — Drap. 



Moll. Ter. et Fluv. France, p. 42, pi. 1, f. 39, 40, 41.— 



Voith in Sturm. Deutseh. Fauna, pt. 3, pi. 4. — Brard, 



Coq. Envir. Paris, p. 157, pi. «, f. 12, 13, 14.— C. Pfeif. 



Deutseh. Land und Siissw. Moll. pt. 1, p. 81, pi. 4, f. 11. 



— Lam. Anim. s. Vert. (ed. Desh.) vol. viii. p. 387. — 



Nii.ss. Moll. Suec. Ter. et Fluv. p. 73. — Kickx, Moll. 



Brabant, p. 63. — Rossmassl. Iconog. Land und Siissw. 



Moll. pt. 2, p. 10, pi. 7, f. 117. — Gras, Moll. Ter. et 



Fluv. France, p. 57, pi. 4, f. 30. — Mermet, Moll. Pyren. 



p. 59. — Stein, Schnecken Berlins, pi. 2, f. 25. 



Helix crassa, Da Costa, Brit. Conch, p. 16, pi. 4, f. 11. 



„ umbilicata, Polt. Hutching, Hist. Dorset, p. 47. 



