Subjcunilics, Goiera, and Subgenera — Recent and Fossil 75 



Species Considered as Valid. The American species included in tliis 

 subgenus are: 



Gyraiilus (Torqids) aeruginosus GtjmuJus (Torquis) parvus (Say) 



Morelct Gyrauhts (Turquis) mntacruzensis 



Gyrauluti (Torquis) arizonensis (Germain) 



Pilsbry and Ferriss Gyrnuluj< (Torquis) siniildris 



Gyraulus (Torquis) allissimus (F. C. Baker) 



(F. C. Baker) Gyraulus (Torquis) vcrDiicularis 



Gyraulus (Torquis) carus (Gould) 



Pilsbry and Fcrriss (hjrnulus (Torquis) vermicukiris 



Gyraulus (Torquis) circuinstrint as hendcrsoni Walker 



(Try on) 

 Gyra ul us ( Torq uis ) circ u ni s[ ria tus 



u'nlkcri Vanatta 



Geological Distribution. Torquis apparently dates geologically from 

 the Oligocene period. Torquis siliceus Pilsbry and Brown, Oligocene of 

 Dry Hill, Antigua. 



Remarks. Except for some small details in genitalia, referred to on a 

 ])revious page, the subgenus Torquis is similar in anatomical details to 

 typical Gyraidus. It is, however, a convenient name for the smaller species 

 with 'reamed out' left side, like parvus and vermicularis, which have nar- 

 rower and smoother whorls than the species of typical Gyraulus, like alhus 

 and de flee tus. 



Genus ARMIGER Hartmann, 1840 



Type by designation of Hartmann in 1842, Nautilus crista Linn. 



1840. Armiger Hartmann, Syst. ubers. Em-op. Gatt., table. 



1842. Armiger Hartmann, Erd-und Siiss. Gasterop., V, pp. 172, 219. Tyjie Armiger 

 cristatus Drap. = Nautilus crista Linn. 



1847. Nautilus Gray, Proc. Zool. Soc, p. 181. Type Turbo nautilus Linn. 



1850. Nautilina Stein, Leben. Schneck. und Musch. Berlins, p. 81. Ideogenotype Pln- 

 norbis nautilus Stein = Planorbis cristata Drap. Type designation by Lind- 

 holm in 1926. 



1885. Armiger Westerlund, Fauna Palaearc. Reg., V. i*. 65. No type cited. As sub- 

 genus of Planorbis. 



1902. Aryniger We.sterlund, Rad. Jugoslav. Akad., 151, p. 121. Type Turbo nautilus 



Linn. As subgenus of Planorbis. 



1903. Spiniformis Germain, Bull. Soc. Sci. Nat. Quest France, ii. III, p. 204. Vide 



Germain, 1931. 

 1905. Armiger Dall, Ala.ska Moll., pp. 83, 86. Type Planorbis crista (Linn.). As sec- 

 tion of subgenus Gyraulus. 

 1918. Armiger W.alker, Miscel. Contr., Mus. Zool., Univ. Mich., No. 6. pp. 13, 94. 



Tj'pe Planorbis crista (Linn.). As section of subgenus Gyraulus. 

 1923. Armiger Germain, Rec. Ind. Mus., XXI, pp. 8, 153. Type Plariorbis crista 



(Linn.). As subgenus of Planorbis. 

 1923. Armiger Wenz, Fossil. Cat., Pars 22, p. 1625. Genotype Gyraulus (Armiger) 



crista (Linn.), As subgenus of Gyraulus. 

 1926. Armiger Lindholm, Archiv. fiir Mollusk., 58 year. Heft 6, p. 253. Monogenotype 



Armiger cristatus T)rap. = Planorbis crista (Linn.). As genus on conchological 



grounds. 



1928. Armiger F. C. Baker, Fresh-water Moll, of Wisconsin, I, p. 385. Type Nautilus 



crista Linn. As subgenus of Gyraulus. 



1929. Armiger H.\As, Trab. Mu.seo Cien. Nat. Barcelona, XIII, p. 386. Type evidently 



Nautilus crista Linn. As genus. 



