101 



ACTEON. Montfort— Leach, 



Tornatella Lamarck. 



Gen. Char. A convoluted, elongated, uni- 

 valve, with a projecting spire ; aperture ob- 

 long, entire, with a sharp edged lip ; colu- 

 mella furnished with a spiral callus or thick 

 plait at its base; operculum oblong, cor- 

 neous. 



Most of the species of Acteon are similar in form, but 

 differing in proportion ; they are also generally striated 

 transversely, and often elegantly colored ; the aperture 

 is perfectly longitudinal, and above two thirds the length 

 of the shell, acute-angular above, and rounded below, 

 the edge thickening, and uniting with the base of the 

 columella forms the callus or what is commonly called 

 the single plait upon it ; other plaits sometimes occur 

 upon the colummella ; the inner lip is very thin, and ap- 

 plied close to the shell. Voluta tornatilis the type of the 

 Genus is a British marine shell, the inhabitant of which 

 forms deep furrows when traversing the sandy shores 

 it loves to frequent. 



ACTEON NoiE. 



TAB. CCCLXXIV. 



Spec. Char. Oval, transversely striated, with 

 one plait at the base of the columella ; striae 

 equidistant, numerous, impressed, obscurely 

 decussated, lip sulcated within. 



The only character except the want of color, by which 

 this fossil can be distinguished from the recent Acteon 



