HELTCID^. 55 



aperture semioval, internally generall}'- contracted ; peristome 

 labiate, furnished with numerous teeth, or very rarel}^ simple ; 

 sometimes the apertural paries is unidentate at the external 

 angle. B. quinquedentatus, Miihlf. (xcix, 69). 60 sp. Mostly 

 Eastern Europe and W. Asia. 



ODONTOSTOMUS, Beck, 1837. (Cyclodontina, Beck [part], 183Y.) 

 Shell rimately perforate, cylindrically fusiform ; spire elongate, 

 turreted ; last whorl compressed at the base, often externally 

 scrobiculate ; aperture oblong, contracted, with from 3 to 6 

 teeth ; parietal wall with an intrant lamella ; peristome expanded, 

 reflexed, the margins approximate, joined by a thin callus. B. 

 Pantagruelianus, Mor. (xcvii, 8). .35 sp. Brazil, Argentine 

 Republic. 



Macrodontes, Swains., 1840. Shell bulimiform ; spire longer 

 than the aperture, which is surrounded with large teeth ; lips 

 united, the outer large, dilated, reflected. B. odontostomus, 

 Sowb. 3 sp. Brazil, Buenos Ayres. 



Plagiodontes, Doring. Shell ovate, aperture with many teeth 

 and a transverse plait behind ; jaw strongly ribbed. La Plata to 

 Patagonia, So. America. F. dentatus, Wood. P. dsedaleus, 

 Desh. 



ToMiGERUS, Spix, 182T. 



Distr. — T. principalis, Sowb. = gibberulus, Burrows (xcvii, 

 9). 5 sp. Brazil, Venezuela. 



Shell perforate, turbinate-globular, last whorl ventricose, 

 aperture rounded or triangular, turned upward, vertical ; peris- 

 tome expanded or reflected, the lips joined by a callus ; interior 

 of aperture contracted by numerous entering lamellae. 



Anostoma, Fischer, 1807. 



Syn. — Tomogerus, Montf., 1810. Angystoma, Schum., 1817. 



Distr. — 5 sp. Brazil. A. globulosa, Lam. (xciii, 1). 



Shell orbicular-depressed ; spire convex, more or less obtuse ; 

 last whorl abruptly turned upwards at the aperture, which thus 

 faces dorsally, has reflected peristome, thickened and dentate 

 within, its extremities connected by a callus, which is also den- 

 tate. Jaw smooth. 



Bingicella, Grsij. Peristome perforated by a small canal. A. 

 globulosa^ Lam. 



BoYSiA, Pfeiffer, 1850. 



Syn. — E[3'postoma, Albers, 1850. Hypostrema, Albers, 1860. 



Distr. — B. Bensoni.1 Pfr. (c, 98 ). Bengal. 



Shell conic-globose, thin, umbilicus a shallow slit, last whorl 

 ascending on the spire ; aperture oblique, subrotund, without 

 teeth, turned upwards ; peristome thick, not reflected, the extrem- 

 ities joined by a callus. 



