PLANORBIS. 153 



than on the upper disk, which is flat, or has the inner coils 

 a little elevated. Body much less high than broad, nearly 

 equally wide above and below, well rounded on the lower 

 disk, and shelving upwards from thence so as to form a 

 keel-like angulation with the superior flattened surface. 

 Mouth rounded, oval, entire, occasionally detached from 

 the preceding coil, broader than long, filling quite two- 

 fifths of the total width, projecting below the basal level. 

 Outer lip acute, disposed to expand. Diameter from an 

 eighth to a tenth of an inch. 



The animal is pale-grey. 



This minute and elegant water-snail may be found on 

 plants in ponds and ditches in most parts of England, 

 Ireland, and the south and middle of Scotland. Aberdeen 

 (Macgillivray) ; Isle of Man (E.F.). 



P. cARiNATUs, Muller. 



Highly polished, smooth or nearly so, strongly carinated, and 

 planulately depressed. 



Plate CXXVII. fig. 4, 5. 



HelLt: pla7iorbis, Linn. Syst. Nat. ed. 12, p. 1242 (in part). — Turt. Concli. 



Diction, p. 45. — Dillw. Recent Shells, vol. ii. p. 896. 

 Planorbis carinalus, Muller, Hist. Verm. pt. 2, p. 157. — Fleming, Brit. 



Animals, p. 279. — Turt. Manual L. and F. W. Shells, 



p. 106, pi. 8, f. 89 (error for 87). — Gray, Manual L. 



and F. W. Shells, p. 262, pi. 8, f. 89.— Brown, Illust. 



Conch. G. B. p. 32, pi. 14, f. 35, 36, 37.— Drap. Moll. 



Ter. et Fluv. France, p. 36, pi. 2, f. 13, 14, 16.— Voith 



in Sturm. Deutsch. Fauna, pt. 3, pi. 5. — Brard, Coq. 



Paris, p. 150, pi. 6, f. 3. — Lam. Anim. s. Vert. (ed. 



Desh.) vol. viii, p. 383. — C. Pfeif. Deutsch. Land und 



SUssw. Moll. pt. 1, p. 76, pi. 4, f. 5, 6. — Nils. Moll. 



Suec. Ter. et Fluv. p. 81. — Kickx, Moll.Brabant. Austral. 



p. 65. — RossmAssl. Iconog. Land und Siissw. Moll. pt. 



1, p. 102, pi. 2, f. 60. — Cantraine, Mem. Acad. Brux. 



vol. xiii. p. 166. — Gras, Moll. Ter. et Fluv. France, 



p. 59, pi. 4, f. 39. — Hartm. Erd und SUssw. Caster, pi. 



31. — Mermet, Moll. Pyren. p. 62. — Stein, Schnecken 



Berlins, pi. 2, f. 1 9. 

 VOL. IV. X 



