NERITA NERITE. 113 



GENUS NERITA.* 



NERITE OR HOOF-SHELL. 



Generic character. Shell univalve, spirally 

 convoluted, retuse, gibbous, flattish underneath ; 

 aperture semilunar ; columellar lip, truncated, 

 flattish, straight, and oblique to the axis of the 

 shell. 



OBSERVATIONS ON THE SHELL AND ITS 

 INHABITANT. 



There is no genus more easily distinguished 

 than that of the Nerites. The semilunar aper- 

 ture and straight flat columellar lip are its 

 decided characteristics. There are a few species 

 which might pass for Turbines, the columellar 

 lip not preserving its straightness ; but even in 

 these doubtful shells it is flat, and therefore their 

 proper place in this genus is obvious. Some of 

 the species have an umbilicus ; and in some the 

 columeilar lip is beset with strong teeth. The 

 Nerites are all either fluviatile or marine, the 

 latter are distinguished by their solid and sub- 

 stantial shells. 



Nothing can exceed the beauty and delicacy 

 of the miniature painting with which many of 

 this genus are adorned ; when viewed through a 

 microscope, the most highly finished touches 

 are discernible. Many species have elevated 



* Plate V. figures 4, 5. 

 10* 



