64 



ZoNiTEs NiTiDULus (The Dull Snail). Draparnaud. 

 Figures 35 and 36. 



c^ 



Added by Mr. Grey, and published in the " Medical 

 Repository y" \n 1821. 



The shell of the above species is in some degree 

 flattened, and has a large and deep umbilicus. There 

 are from four and a half to five convolutions. The 

 colour is a pale or yellowish -horn above, being of a rather 

 lighter hue beneath. It is opaque vrhite around the 

 umbilicus. The shell is well marked with longitudinal 

 wrinkles. The aperture is rather oblique, and some- 

 what crescent shaped, being not so high as it is wide. 

 A noticeable circumstance is the dull waxen appearance 

 of the shell. 



The diameter is three tenths of an inch. 



The colour of the animal is leaden, being darker than 

 that of Zonites cellarius, which it closely resembles in 

 form. 



There is a variety named Zonites Helmii, which is 

 more transparent, and of a greenish-white tint. 



Zonites nitidulus is frequently mistaken for a small 

 specimen of Zonites cellarius, a little care being requi- 

 site to recognize the difference. It chiefly varies from 

 the cellar snail in the shell being more concave beneath 

 and more convex above than that species. It is also 

 smaller, darker coloured, not so shiny, has a larger um- 

 bilicus for its size, the aperture less oblique, and the 



