Subfamilies, Genera, and Subgenera — Recent and Fossil 51 



Radiila with interstitial cusps on laterals or marginals: Australorbis, Twpicorbis. 



Jaw in three pieces, a superior and two lateral jaws: Tropicorbis, Auslralorbis, 

 Ajroplanorbis. 



Jaw fragmented with many plates: Planorbis, Bathyomphalus, Anisus, Gyraulus, 

 Armig( r. 



^'erge with stylet : Anisus, Bathyomphalus, Gyraulus. 



Verge without stylet: PUmorbis, Armiger, Tropicorbis, Ajroplanorbis, Auslralorbis. 



Several groups are unknown anatomically and hence their position in 

 the system can not be definitely known until the animal has been examined. 

 Such are Costorbis, Syrioplanorbi)^, Taphius, and Biomphalaria. The fossil 

 group supposed to belong to this subfamily, Odontogyrorbis, can only be 

 placed by shell resemblances and this points to the Planorbinae. 



■ Genus PLAXORBIS Cleoffroy, 1767 

 Genotj'pe by tautonomy Helix planorbis Linn. 



1767. Planorbis Geoffroy, Traite Coq., Paris, p. 12. No tj'pe designation. 



1774. Planorbis Muller, (part) Verm. Terr. Hist., II, p. 152. No type designation. 



1833. Anisus Fitzi.n-ger. (part) Beitr. Lande.sk. Oester. Ill, ]k 111 (Xon Dejean. 1821, 

 Coleoptera). 



1847. Spiralina H.\rtm.\nx, Herrmannsen, Ind. Gen. Mai.. 11, V- 286. As synonym of 

 Planorbis. 



1850. Tropidiscus Steix, Schn. u. Muscheln Berlins, p. 76. As subgenus. Tj'pe desig- 

 nated by Clessin, 1886 — Planorbis marginatus Drap. 



1852. Anisus [Fitzixger] Herrm.\xxsex, Ind. Gen. Mai., Suppl. p. 9. Tjqie: Pla- 

 norbis umbilicatus Miiller. As fixed b,v Gray, 1847. Xot Anisus Studer, 1888. 



1855. GyrorbU Moq.-T\xd., (part) Hist. Xat. Moll. Terr, et Fluv. France, II, p. 428. No 

 type cited. As genus. 



1855. Omalodiscus Bexsox, Jour. Asiatic Soc. Bengal, XXIV, p. 127. T3-pe designated 

 by Kennard and Woodward, 1924, Omalodiscus marginatus Drap. 



1883. Tropidiscus Fischer, Man. Conch., p. 509. Xo type designation. As section. 



1885. Tropidiscus Westerluxd, Fauna Palaearc. Reg., V, p. 64. X"o type cited. As sub- 



genus of Planorbis. 



1886. Tropidiscus Clessix, Syst. Conch.-Cab.. XVII, p. 34. Type Planorbis marginatus 



Drap. As subgenus. 

 1898. Planorbis (Geoffroy) vox M.artexs, Biol. Centr. Amer., :Mo11.. p. 380. Xo type 



cited. As genus. 

 1902. Tropidiscus Westerluxd, Had. Jugoslav. Akad., 151, p. 120. Genotype Helix 



planorbis Linn. As subgenus. 

 1905. Placorbis DR.\p.\RX.\rD, X'at. Hi.st. Moll. France, p. 138. (vide Lindholm, Archiv. 



fiir Mollu.sk., 58 year. Heft 6. p. 252). 



1905. Tropidiscus D.\ll, Alaska Moll., p. 85. Type Planorbis umbilicatus Muller = 



Planorbis complanatus Stein. 



1906. Otnalodiscus D.\ll. X'autilus XIX, p. 105. Comments on nomenclatorial position 



but cites no type. 

 1917. Tropidiscus Sees. Ann. Musei X'at. Hungarici, XV, pp. 40, 141. Type Tropidiscus 



planorbis (Linn.). As genus. 

 1921. Tropidiscus Germaix'. Rec. Ind. Mus., XXI, p. 7. Type Planorbis planorbis 



(Linn.). As subgenus. 

 1923. Planorbis (of Muller 1774) Wexz, Fossil. Cat., Part, 22, p. 1523. Genotype 



Planorbis planorbis (Linn.). As genus. 



1926. Tropidiscus (of Stein) Lixdholm. Archiv. fur Mollusk., 58 year. Heft 6. p. 252. 



Ideogenotype Helix planorbis Linn. As genus. 



1927. Planorbis Kexx.ard and Woodw.xrd, Syn. British Xon-Marine !Moll., p. 66. Tj'pe 



by tautonomj' Helix planorbis Linn. As genus. 



