PLANORBIS. 149 



P. albus, Mtiller. 



Small, rather depressed, slightly convex on both disks, whorls 

 with decussating striee, and pilose. 



Plate CXXVI. fig. 1, 2. 



Planorlis alius, Muller, Hist. Verm. pt. 2, p. 164. — Jeffreys, Trans. Linn. 



Soc. vol. xvi. p. 387. — Fleming, Brit. Anirn. p. 279. — Turt. 



Manual L. and F. W. Shells, p. 114, f. 97. — Gray, Manual 



L. and F. W. Shells, p. 259, pi. 8, f. 197.— Macgilliv. Moll. 



Aberd. p. 119. — Brown, Illust. Conch. G. B. p. 31, pi. 14, 



f. 52, 53. — C. Pfeif. Deutsch. Land und Slissw. Moll. pt. 1, 



p. 80, pi. 4, f. 9, 10. — Dupuy, Moll. Gers, p. 47. — Stein, 



Schnecken Berlins, pi. 2, f. 23. 



Helix alba, Mont. Test. Brit. p. 459, pi. 25, f. 7. — Maton and Rack. Trans. 



Linn. Soc. vol. viii. p. 192. — Dorset Catalog, p. 53, pi. 19, f. 18. — 



Turt. Conch. Diction, p. 48. — Dillw. Recent Shells, vol. ii. p. 909. 



Planorlis Mspidus, Drap. Moll. Ter. et Flu v. France, p. 43, pi. 1, f. 45 to 48. — 



Brard, Coq. Paris, p. 159, pi. 6, f. 6, 7. — Voith in 



Sturm. Deutsch. Fauna, pt. 4, pi. 5. — Lam. Anim. s. Vert. 



(ed. Desh.) vol. viii. p. 387. — Nils. Moll. Sueciae Ter. et 



Fluv. p. 75. — Kickx, Moll. Brabant. Austral, p. 64. — 



Gras, Moll. Ter. et Fluv. France, p. 57, pi. 4, f. 32. — 



Mermet, Moll. Pyren. p. 59. 



„ Jiirsutus, Gould, Invert. Massach. p. 206, f. 135 ? 



Gyraulus Mspidus, Hartm. Erd und Siissw. Gaster. pi. 25, 



Shell small, pale horn- coloured, rather depressed (about 

 thrice as broad as high), very thin, not much polished. 

 Upper disk flattish, slightly sunk, quite in the centre ; 

 concavity of lower disk more extended, not profound. 

 Whorls four or five, deeply divided, simply and moderately 

 rounded, of toLerably fast increase, not peculiarly narrow, 

 adorned with fine close-set raised spiral lines that are 

 decussated by still finer and more crowded spiral ones, and 

 are clothed, when recent, with a deciduous pile. Body 

 decidedly broader than high, about equally wide on either 

 disk ; its slopes nearly equal ; rather narrowly rounded at 

 the periphery, at times assuming a subcarinated appearance 



