176 PROCEEDINGS OF THE MALACOLOGICAL SOCIETY. 



The synonymy of Risso's Theba, when restricted as just mentioned, 

 according to our reading, should be as follows : — 



Genus Theba, Risso, 1826. 



Type, Helix cartusiana, Miiller (selected by Pilsbry, 1895). 



1819. Teba [pars] : Leacli, Synop. Moll. Brit., proof sheets, p. 91. 



1821. Helirella [pars]: Ferussae, Tabl. syst. Limagons, Jan. ed., p. 41 



(Juneed., p. 37). 

 1821. Zcnobia [pars]: Gray, London Med. Repos., xv, p. 239. [Non 



Oken, 1815 (Lepidopt.).] 

 1826. Theba (Leach MS.): Risso, Hist. Nat. Europ. m^rid., iv, p. 73. 

 1833. Monncha [pars] : Fitzinger, Beitr. Landesk. Oesterr., iii, p. 95. 



[Non Monachus, Kaup, 1829 (Aves).] 

 1837 Bradybcena [pars]: Beck, Index Moll., p. 18. [Non Bradvbcenvif, 



Dejean, 1829 (Goleopt.).] 



1837. Fruticicola [pars] : Held, Isis, xxx, lift. 12, col. 914. 



1838. Cernuella [pars] : Schliiter, Kurz. syst. Verzeichn., p. 6. 

 1871. Carthusiana : Kobelt, Cat. Europ. Binnenconch., p. 11. 



1889. Latonia : Wester lund. Fauna Palaarct. Region, ii, pp. 30 and 68. 



[Non Meyer, 1843 (Rept.).] 

 1889. Euomphalia : ib., pp. 31 and 92. 

 1904. W esterlundia : Kobelt, in Rossmassler's Icon., N.F. xi, pp. 131 and 



181 [n.nov. for Latonia]. 



Ferussac's first group, Lomastomae, need not be dwelt on at length. 

 It comprised thirty-seven species, two of which are indeterminate, 

 while two are now referred to Zonitidae, and one to Pupillidse, the 

 remaining thirty-two being distributed among various genera of 

 the Helicidae, as shown in the list with which this paper concludes. 



The Aplostomse, on the other hand, since they include Ferussac's 

 " Helicella, Lamarck ", demand a close scrutiny. They were divided 

 by Ferussac into : " Les Pesons, Verticilli," ten species ; " Les 

 Hyalines, Hyalince," twenty-three species ; and " Les Rubannies, 

 Fasciatw," twenty species. In the first subgroup are seven 

 species now referred to Pyramidula, Punctum, Patula, Helicodiscus, 

 and Goniocliscus {i.e. the Helix of Humphrey et alii) ; and three, 

 algira, Linn, (the type), with verticillus, Fer., and gemonense, Fer., 

 belonging to Montfort's prior genus Zonites. With a few exceptions 

 the Fasciatse are now placed in genera belonging to one or other 

 of the numerous subfamilies of Zonitidae. Hence Helicella, Fer., s.s., 

 comes into use for the bulk of the Hyalinae, with Helix cellaria, 

 Miiller, as the type (fixed by Gray in 1847).^ 



Three distinct genera have since been formed for certain species 

 of the group, namely, Vitrea, Fitzinger, 1833, Petasina, Beck, 1847, 

 and Zonitoides, Lehmann, 1862. The synonymy of the four genera 

 will therefore run as follows : — 



^ "List of Genera of Recent Mollusca " in Proc. Zool. Soc, 1847. This 

 reference applies to all the citations from Gray for that year. 



