is: 



broad, flat, thin, and stands obliquely to the side of the 

 shell, f. Cornwall. 



GENUS. BULUEA. 

 Extremely thin, somewhat involute on one side, and 



destitute of a columella or spire ; aperture large 



and expanded. 



B. APERTA. Lam. BULLA K.Lin. 1183. Sow. G. 

 f. l.D.p. 477. Ch. f. 1354,5. Dow. t. 220. 

 Mont. p. 208, via. 2./ 1.3. Da. Cos.t.Z.f. 3. 

 Suborbicular, thin, glossy, pellucid, brittle, white, 

 slightly wrinkled, no external convolution or umbi- 

 licus ; inner lip very small, slightly involuted, visible 

 to the end ; aperture occupying nearly the whole of the 

 shell. 0,70. Devonshire, Kent, fyc., common. 



B. PUNCTATA. Clark. Z. J. 3. p. 339. BULLA P. 

 Adams. Lin. T.^.t I./. 6, 8. F. p. 294. Ovate- 

 oblong, extremely thin, white, pellucid, glossy, marked 

 with transverse dotted lines ; inner margin arcuated ; 

 apex obtuse with a very shallow umbilicus. 0,10. 

 Exmouth and Torquay in pools at the lowest spring 

 tide, very rare. 



B. PRUINOSA. Clark, in Z. J. 3. p. 339. Sub- 

 globose, subopaque, dead frosted white, delicately 



