Subfmnilies, Genera, and Subgenera- — Recent and Fossil 79 



collected in Poland. These differences may all be individual. The group 

 merits additional anatomical study. 



(k'nus TAPHIUS H. and A. Adams, 1855 



T.ype by original designation Planorbis nndecolus Orb. 



1855. Taphius H. and A. Ad.\ms, Genera, II, p. 262. Type Planorbis andecolus Orb. 



1870. Taphius D.all, Ann. N. Y. Lye. Nat. Hist., IX, p. 351. Tj'pe Planorbis andecolus 



(H. and A. Adams, error for Orb.). As subgenus of Planorbis 



1883. Taphius Fischer, Man. de Conch., \). 507. Type Planorbis andecolus Orb. As 



section of Planorbis 



1884. Taphius Tryon, S. and S. Conch., Ill, p. 106. Type Planorbis andecolus Orb. As 



subgenus of Planorbis 



1886. Taphius Clessin, Syst. Conch. Cab., XVII. p. 33. Type Planorbis andecolus 

 Orb. As subgenus of Planorbis 



1899. Taphius Martens, Biol. Cent. Amer., Moll., p. 396. Mentions Planorbis sub- 

 pronus Martens. As subgenus of Planorbis 



1905. Taphius D.\ll, Alaska Moll., p. 81. Type Planorbis andecolus Orb. As sj'nonym 

 of Helisoma 



1921. Taphius Germain, Rec. Ind. Mus., XXI, pp. 7, 62. Type Planorbis andecolus 

 Orb. As subgenus of Planorbis 



1924. Taphius Pilsbry, Proc. Acad. Nat. Sci. Phil., 86, p. 49, plate 4. Variation of Pla- 

 norbis andecolus Orb. 



1930. Taphius H. B. Baker, Oc. Papers, Mus. Zool. Univ. Mich., 210, p. 43. Monotype 



Planorbis andecolus Orb. As genus 



1931. Taphius Thiele, Handbuch, Part 2, p. 479. Type Planorbis andecolus Orb. As 



.-section of Planorbis 



Shell (plate 77, figs. 13-15). Sinistral, whorls few, raindly increasing 

 in diameter, the body whorl wide and much enlarged; spire greatly de- 

 pressed below the level of the body whorl, the spire whorls bluntly angu- 

 late; umbilical side flattened; all the whorls visible and nearly in the 

 same plane; aperture large, expanded; no lamellae within the aperture. 

 Animal. The characteristic of the animal and its anatomy have not 

 been described. 



Geographical Distribution. South and Central America from southern 

 Mexico to Peru and Bolivia. 



Species Considered as Valid. Only five species are here referred to 

 Taphius. 



Taphius andecolus (Orb.) Lake Titicaca, Peru 

 Taphius moiitanus (Orb.) Lake Titicaca, Peru 

 Taphius titicacensis (Clessin) Lake Titicaca, Peru 

 Taphius pronus (Martens) Venezuela 

 Taphius s}ibpronus (Martens) Mexico 



Geological Distribution. Not definitely known. T(tph{}(s pronus has 

 been found fossil in Lake Valencia, Venezuela, probably of Pleistocene age. 



Remarks. The systematic position of the genus Taphius is greatly in 

 doubt because its anatomy is unknown. Some of the species, as pronus and 

 subpronus, resemble certain species of Tropicorbis and Taphius may be 

 another genus of Planorbidae peculiar to both Central and South America. 

 Typical andecolus bears a striking resemblance to the tyi')ical group of 

 Helisoma and Dall (1905) made Taphius a synonym of that group. 

 Cermain (1921) makes it a subgenus of Planorbis allied to Helisoma. 



