78 PLANOKBIDiE 



1862. Planorhis glaber, Jeffreys: Jeffreys, Brit. Couch., i, 



p. 85, V, pi. V, f. 5. 



1863. Planorhis glaber, Jeffreys: Reeve, L. & F.-W. Moll. 



Brit. Is., p. 140, figs. 



First recorded as British in 1838, by J. Alder. (See ref. 



above.) 

 British Distribution in Time : Cromerian to Recent. 



6. fPlanorbis (Gyraulus) arcticus (Beck MS.), Moller. 

 Etym. : — Lat. arcticus, northern. 



1838. Planorhis articus, B. : Beck, Indcjo Moll., p. 123. [Nom. 



nud.'\ 

 1842. Planorhis arcticus. Beck: Moller, ■/ntZej; Moll. Grcenl., 



p. 5. 

 1855. Planorhis (Nautihna) arcticus. Beck : H. <fe A. Adams, 



Genera Moll., ii, p. 263. 

 1857. Planorhis {Nautilina) arcticus, Bk. & Moll. : Morch, in 



Rink, Gronland, ii, " Naturh. Bidr," p. 76. 

 1885. Planorhis {Gyrauh(s) arcticus, Beck : Westerlund, 



Fauna Paldarct. Region, v, p. 77. 

 1905. Planorhis (Torquis) arcticus, Moller : Dall, Harriman 



Alaska Exped., xiii, p. 96. 



First recorded as British in 1903, by B. B. Woodward 



(Journ. of Conch., x, pp. 355 & 363). 

 British Distribution in Time : Pleistocene. 



7. Planorbis (Gyraulus) acronicus, Ferussac.^ 



Etym. : — From Acronius lacus, the old name for Lake Ueber- 

 lingen, part of Lake Constance. {Fide Pomponius Mela.) 



1805. Planorbis spirorbis, Mull. : Draparnaud, Hist. Moll. 



France, p. 45, pi. ii, f. 8-10. [From an 



inspection of the types. Non Linne, nee 



Midler.] 

 1807. Planorbis acronicus : Ferussac, Essai method. Conchyl., 



p. 105. 

 1807. Planorhis defortnis : Ferussac, I. c. 

 1821. Planorhis hispidus, var. /?. deformis [Fer.] : Hartmann, 



Neue Alpina, i, p. 255. 

 1837. Planorbis deformis, Lam. : Alder, Mag. Zool. & Bot., 



ii, p. 113. [Non Lamarck.] 

 ?1838. Planorbis devians, Porro : Porro, Malac. Prov. Comasca, 



p. 84, pi. i, f. 6a-c. [Porro cites as synonym 



" Planorbis suhstriatus Meg. in litteris."] 

 1841. (Planorhis) Gyraulus deformis [Fer.] : Hartmann, Erd- 



<& Sussw.-Gasterop., p. 95, pi. xxvii, xxxv & 



xxxvi. [Non Lamarck, 1822.] 



1 For the history of this species, See Kennaed & Woodward, Proc 

 Malac. Soc. Lond., xvi, 1924, p. 12. 



