86 PLANORBIDJE 



1873. Planorbis {Tropidisciis) rotundatus, Poir. : Wester- 



LUND, Fmma Moll. Svec, p. 385. 

 1875. Planorbis (Gyrorhis) calculiforniis, Sandberger : Sand- 



BERGER, Land- (& Siissw.-Conch. Vorwelt, 



p. 779, pi. xxxiii, f. 20. 

 1885. Planorbis (Gyrorhis) leucostoma, Miill. [sic] : Wester- 



LUND, Fauna Palaarct. Region, v, p. 73. 

 1897. Planorbis (Diplodiscus) spirorbis, var. leucostoma, Mill. : 



Westerlund, Acta Soc. Fauna d Flora 



Fenn., xiii, no. 7, p. 117. 

 1909. Wuestia rotundatus (Poiret) : Honigmann, Zeitsch. f. 



Naturw., Ixxxi, p. 296. 

 1913. Planorbis (Paraspira) rotundatus, Poiret : Germain, 



Moll. France, ii, p. 255, f. 301. 

 1913. Planorbis (Paraspi.ra) Perezi, Graells, in Dupuy : Ger- 

 main, t. c, p. 255. 

 1913. Planorbis (Paraspira) fragilis, Millet: Germain, i.e., 



p. 255. 



[Germain {Rec Indian Mus., xxi, 1922, p. 89) states 

 that Planorbis Villcp., Adami, is a local variety of this 

 species.] 



First recorded as British in 1803, by G. Montagu, as 

 PI. spirorbis {Test. Brit., p. 455, pi. xxv, f. 2). 



British Distribution in Time : Cromerian to Recent. 



14. Planorbis (Bathyomphalus) contortus (Linne). 

 Etym. : — Lat. contortus, twisted round [on itself]. 



1758. Helix contorta : Linn^us, Syst. Nat., ed. 10, p. 770, 



no. 589. 

 1767. Helix contorta : Linn^us, o. c, ed. 12, p. 1244, no. 673. 

 1774. Planorbis contortus : Muller, Verm. Hist., ii, p. 162. 

 1778. Helix crassa : DaCosta, Test. Brit., p. 66, pi. iv, f. 11. 

 1791. Helix contorta: Gmelin, in Linn. Syst. Nat., ed. 13, i, 



pt. 6, p. 3624, no. 37. 

 1799. Helix umbilicatus [sic] : Pulteney, Cat. Dorset., p. 47. 

 1801. Planorbis contortus: Draparnaud, Tabl. Moll. France, 



p. 43. 

 1803. Helix contorta, Lin. : Montagu, Test. Brit., p. 457, 



pi. xxv, f. 6. 

 [According to Montagu (Test. Brit., Suppt., p. 146) this 

 species occurred in the Portland Collection under the 

 name of Helix complanata.] 

 1805. Planorbis contortus, Linn. : Draparnaud, Hist. Moll. 



France, p. 42, pi. i, f. 39-41. 

 1807. Helix contortus, Linn. : Maton & Rackett, Trans. Linn, 



Soc, viii, p. 191. 



