NERITANERITJS. 113 



before mentioned. It inhabits the coasts of 

 Europe, Asia, and Africa, and is common in 

 the Mediterranean. A few specimens have been 

 picked up on the Welsh coasts, but these were 

 probably driven there by storms. 



HELIX Obscura. 



SMALL BROWN SNAIL. 



Specific Character. Shell sub-oval, rather 

 obtuse, opaque, with about six longitudinally 

 wrinkled whorls ; aperture roundish, lunar ; it is 

 of a brownish horn colour, and the outer lip 

 white, with a reflected margin ; length half an 

 inch, breadth one fourth, or one sixth. These 

 shells are usually covered with an epidermis, 

 which varies according to the situations they 

 occupy ; and the colour being regulated by that 

 of the substance to which they attach them- 

 selves, they thus escape observation. 



Genus-NERITA.* Plural, Nerita. 



NERITE OR HOOF-SHELL. 



Generic Character. Shell univalve, spirally 

 convoluted, retuse, gibbous, flattish underneath ; 



* Plate V. figures 4, 5. 

 I 



