HELIX. 



139 



pressed to the base of the shell, so as to cover the umbili- 

 cal opening, as is usual, it makes a curved line around 

 the umbilicus, and projects perpendicularly from the 

 base. 



The smooth, amber-colored, finely striated variety is 

 rare, and differs so much n-om the common type that it 

 induces those who are not well acquainted with the spe- 

 cies to consider it distinct. But the character of the 

 aperture is the same in both ; and all the intermediate 

 modifications may be seen in the various collections. 



Mr. Say's description was pubUshed in January, 1821 ; 

 and the shell has been known in the United States by 

 the name of H. palliata since that time. In 1822, the 

 name of H. denotata was applied to it by F^russac. The 

 editors of the new edition of Lamarck's Animaux sans 

 Vertebres, have chosen to retain the latter name ; but, 

 inasmuch as it is inconsistent with the rules of priority, 

 as advocated by themselves, it ought not to obtain. 



Plate XV. represents the variety of this species. 





