HELICIDA. 55 
aperture semioval, internally generally contracted ; peristome 
labiate, furnished with numerous teeth, or very rarely simple ; 
sometimes the apertural paries is unidentate at the external 
angle. B. quinquedentatus, Muhlf. (xcix, 69). 60 sp. Mostly 
Eastern Europe and W. Asia. 
opontrostomts, Beck, 1837. (Cyclodontina, Beck [part |, 1837.) 
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. (xevii, 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. 5. odontostomus, 
Sowb. 38sp. 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. P. dentatus, Wood. P. dexdaleus, 
Desh. 
ToMIGERUS, Spix, 1827. 
Distr.— T. principalis, Sowb. = gibberulus, Burrows (xevii, 
9). 5sp. 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 lamelle. 
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. 
Ringicella, Gray. Peristome perforated by a small canal. A. 
globulosa, Lam. 
BoystA, Pfeiffer, 1850. 
Syn.—Hypostoma, Albers, 1850. Hypostrema, Albers, 1860. 
Distr.—B. Bensoni, 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. 
