141 



umbilicated and as well as the pillar pure white, i... 

 0,20. Near Land's End, Cornwall. The shape not 

 unlike Lignaria but is conical-oval and the volutions 

 more loosely connected. 



B. HYALINA. Turton in Mag. Nat. H. 7. Oval, 

 transparent, smooth, crystalline, the aperture dilated at 

 the base, pillar slightly umbilicated; crown flattened, 

 channelled, umbonate. Newcastle, not uncommon, 

 Land's End. Not unlike Umbilicata but is shorter, 

 more oval, and the aperture more dilated. 



B. UMBitiCATA. Mont. p. 203. t. 7. /. Z.Turt. 

 D.p. 22.- F. p. 293. Lin. T. 8. p. 129. D.p. 

 497. Oblong-oval, smooth, white; apex rounded and 

 umbilicated ; aperture extremely narrow, extending the 

 whole length of the shell and dilating a little at the 

 base, i . . . 0,062 . In sand, Falmouth. 



B. TRUNCATA. Adams in Lin. T. 5. t. 1. /. 1,2 

 Mont. p. 223. t. 7. f. 5.F. p. 293. B. RETUSA. 

 Lin. T. 8. p. 128. D. p. 497. Subcylindric, 

 opaque, white, the upper part longitudinally striated, 

 the lower plain; apex truncated and largely umbili- 

 cated showing the involutions ; aperture linear, dilated 

 slightly at the base and contracted most in the middle. 

 IT. Devon and Cornwall. 



