ON AFROD0NTA'']VrKT,V; AJsf) PONS. 385 



South Africa affords the missing- explanation, and I have 

 made out the following- hypothesis : 



"The toothed Endodontas, such as Thanni atodon, etc., 

 having- their headquarters in Polynesia and New Zealand, 

 migrated by the Eocene Antarctic land (Archinotis) westward, 

 reaching South Africa, where we find theui still living as 

 Af rodonta, and from there they must have found their way 

 across the Eocene Archhelenis to St. Helena, heing knovyjT 

 from there as Helenoconcha." 



Genus f]ND0D0NTA Alhers,^ 1850. 



Sub-genus Endodonta Alhers. 



Section Afrodonta {Melv. ct Pon^.), 1908. 



Shell very small, subdiscoidal, with spire low, convex ; 

 broadly umbilicate, or excavated ; whorls numerous, tightly 

 coiled; periphery i-ounded ; surface very minutely striate or 

 Urate, unicoloured, translucent. Aperture having one or more 

 internal folds upon the outer wall, or the parietal wall, or 

 both, and one tooth-like fold low on the columella or at the 

 base. Except the parietal folds, which sometimes extend on 

 the body whorl beyond the aperture, all are wholly internal, 

 sometimes out of sight from the aperture. Type Endodonta 

 bilamellaris [M. & P.). 



Distribution. — South Africa. 



Endodonta [Endodonta (Afrodonta)] bilamellaris 

 {Melv. & Pom.). PI. XXIV, fig. 18. 



Afrodonta bilamellaris Melv. & Pons., Ann. and Mag. Nat. Hist., 



vol. i (1908). p. 134 pi- 

 vii, fig. 6. 



"A. testa ... conico-depressa, tenui, cornea, profunda 

 • Alhers, ' Die Hel..' p. 89. 



