224 HELICIDyE. 



REMARKS. The color of this shell varies from a light- 

 greenish horn-color to a deep chestnut. The umbilicus 

 varies considerably in size, but it is always distinct and 

 profound. The surface, usually smooth and shining, is 

 sometimes deeply and irregularly wrinkled. The inte- 

 rior of the aperture exhibits, in perfect specimens, a 

 beautiful, pearly lustre. The epidermis is reflected over 

 the edge of the lip into the aperture. 



It has sometimes been confounded with Helix inor- 

 nata ; but it may always be distinguished from that, by 

 attention to the following particulars. It is a much 

 larger shell, yet the number of whorls is constantly one 

 less ; the umbilicus is larger and deeper, the aperture 

 more circular, and the deposit of testaceous matter within 

 is less. The color of the shell is usually much darker. 

 It is, however, much more likely to be confounded with 

 Helix lueubrata, Say, which it more nearly resembles. 

 The difference between them will be pointed out in the 

 remarks on that shell. 



There is considerable confusion between this and the 

 two most nearly allied species. It was indicated by 

 Ferussac, in 1822, by the name of Helix Icevigata of 

 Rafinesque, but without description or figure. That 

 Ferussac referred to this species, and not to the succeed- 

 ing, is clear ; because the word Icevigata could only be 

 applied to a smooth shell. At this time it had become 

 known in cabinets of the United States by the specific 

 name imposed by Dr. Griffith. In 1832 there appeared 

 in Ferussac's work a figure, pi. 82, f. 6, purporting to 



