GASTROCOPTA, SOUTH AMERICA. 101 



P.[upa] dicrodonta DOERING, Apuntes, etc., in Boletin de 

 la Acad. Nac. de Ciencias de la Rep. Argentina, iii, 1879, p. 83. 



' ' This species may be distinguished easily from all the rest 

 by the bifid tooth on the parietal wall of the aperture. It is 

 composed of two parallel ridges, the superior one being pro- 

 longed upward to the position of the insertion of the lip, the 

 other one having a more immersed place, behind the first. 

 The rest of the teeth of the aperture are of smaller size. This 

 species is doubtless the most abundant in the territory of the 

 sierra of Cordoba, etc." (Doering). 



35. GASTROCOPTA IHERINGI (Suter). PL 17, fig. 16. 



The shell is minutely perforate and rimate, convexly taper- 

 ing above, the last two whorls nearly equal in diameter. There 

 are 5% moderately convex whorls, the last one without crest. 

 Apex obtuse. Surface minutely, unevenly striate. The aper- 

 ture is very shortly oval. Peristome thin, expanded through- 

 out, interrupted above. The angular and parietal lamellae 

 are nearly parallel and of about equal length; the angular is 

 sigmoid, its inner end curving towards and joining the pari- 

 etal. Parietal lamella nearly straight, highest where the an- 

 gular joins it. Columellar lamella large, semicircular, its 

 anterior part running forward, inner part curving downward 

 parallel to the axis. The upper and lower palatal plicae are 

 short, high, entering lamina?. Basal fold is large, straight- 

 topped, and nearly radial, transverse to the cavity. Length 

 2.3, diam. above aperture 1.1 mm. 



Brazil: Bollaxa, City of Rio Grande do Sul, subfossil in a 

 modern deposit (H. von Ihering). 



Pupa iheringi SUTER, Revista do Museu Paulista, iv, 1900, 

 p. 336, pi. 3, f. 8, 8a. 



The armature of the aperture is more like that of G. btta- 

 mellata than any other of our northern species, the differences 

 being merely in small details of form, except that the lower 

 palatal plica is more deeply immersed in bilamettata. Figured 

 and described from paratypes. This species is very closely 

 related to G. dicrodonta, perhaps identical ; yet the latter is 

 slightly smaller, with a fraction of a whorl more, and comes 



