PLANORBIS. 147 



which are natives of tropical climates, differ materially in 

 general contour and ornament, from those found in tem- 

 perate regions. 



P. corneus, Linnseus. 



Large, stout, with rounded ventricose whorls ; upper disk 

 concave, lower plane. 



Plate CXXVI. fig. 4, 5. 



Helix cornea, Linn. Syst. Nat. ed. 12, p. 1243. — Penn. Brit. Zool. ed. 4, vol.iv. 

 p. 134, pi. 83, f. 126.— Pulteney, Hutchins, Dorset, p. 47. — 

 Donov. Brit. Shells, vol. ii. pi. 39, f. 1. — Mont. Test. Brit, 

 p. 448, — Maton and Rack. Trans. Linn. Soc. vol. viii. p. 190. 

 — Dorset Catalog, p. 52, pi. 20, f. 13. — Turt. Conch. Diction, 

 p. 47, f. 52.— Chemn. Conch. Cab. vol. ix. pt. 2, p. 93 (in part), 

 pi. 127, f. 1113, 1114.— Dillw. Recent Shells, vol. ii. p. 906.— 

 Index Testaceolog. pi. 33, f. 48. 

 Planorbis purpureus, Muller, Hist. Verm. pt. 2, p. 154 (not var.). 



„ similis, Muller, Hist. Verm. pt. 2, p. 166 (young). 

 Helix nana, Penn. Brit. Zool. ed. 4, vol. iv. p. 133, pi. 83, f. 125 (young). 



,, cornu-arictis, Da Costa, Brit. Conch, p. 60, pi. 4, f. 13. 

 Planorbis corneus, Drap. Moll. Ter. et Fluv. France, p. 43, pi. I, f. 42, 43, 44. — 

 Fleming, Brit. Animals, p. 277. — Jeffreys, Trans. Linn. 

 Soc. vol. xvi. p. 383.— Turt. Conch. Manual, p. 112, f. 95; 

 ed. Gray, p. 258, pi. 8, f. 95.— Brown, Illust. Conch. G. B. 

 p. 31, pi. 14, f. 31, 32, 33.— Brard, Coq. Paris, p. 147, pi. 6, 

 f. 1 , 2. — Voith. in Sturm. Deutsch. Fauna, pt. 4, pi. 4. — 

 Lam. Anim. s. Vert. (ed. Desh.) vol. viii. p. 382. — C. 

 Pfeif. Deutsch. Land und Siissw. Moll. pt. 1, p. 77, pi. 4, 

 f. 3, 4.— Nils. Moll. Suec. Ter. et Fluv. p. 74. — Blainv. 

 Manual Malacol. pi. 37 bis. f. 3. — Sowerby, Genera Shells, 

 Plan. f. 1. — Rossmassl. Iconog. Land und S'ussw. Moll. 

 pt. 2, p. 14, pi. 7, f. 113; pt. 1, pi. 5, f. 86 (animal).— 

 Cantraine, Mem. Acad. Brux. vol. xiii. p. 1 64. — Gras, 

 Moll. Ter. et Fluv. France, p. 57, pi. 4, f. 31. — Dupuy. 

 Moll. Gers, p. 46. — Stein, Schnecken Berlins, pi. 2, f. 15. 

 Planorbe cornee, Chenu, Trait6 Elem. Conch, p. 167, f. 541, 542. 



Shell large, rather strong, glossy, from greyish olive to 

 ferruginous olive (more rarely pallid), not quite thrice as 

 broad as high, with only irregular wrinkles of increase, 

 and very fine close-set spiral strife, that are chiefly appa 



