182 



lix; but the structure of the shell is altogether different 

 either from the Bulla or Helix, and must necessarily be 

 separated from them. The shell is ovate, oblong, or spi- 

 ral, more or less ventricose ; aperture entire, longer than 

 wide; margin very unequal; columella straight, smooth, 

 not truncated, or widened at the base, striated longitu- 

 dinally ; and when the shell has, obtained its maturity 

 a reflected lip is formed, thickened round its circumfe- 

 rence on the right side, and frequently nearly covering 

 the umbilicus on the other. In the B. ovata, the type 

 of this genus, the outer lip has a thickened callosity at 

 the middle part, not mentioned by Lamarck. These 

 shells have no operculum; the substance of some spe- 

 cies is extremely thin, and the margin of the aper- 

 ture smooth and sharp; all of them are supposed to be 

 oviparous, and the eggs of some species are nearly as 

 large as those of a pigeon. Many of the species of this 

 genus are heterostrophe shells, and have never been 

 found with the whorls turned to the right hand, or 

 what are termed dextral shells. 



Bulimus ovatus Bulimus Kichii 



haemastomus inversus 



gallina-sultana citrinus 



zigzag sultanus 



undatus Pythogaster 



