80 THE ELEMENTS 



live specimens can only be had by 

 trawling for them. 



The continental writers on Con- 

 chology, Lamarck, Latreille, <&c. have 

 made a new genus from the Neritce, 

 termed Natica, which embraces the 

 umbilicated kinds, such as the Glau- 

 cina and its corresponding species. 

 We, however, can see no particular 

 reason for making this a generic dis- 

 tinction. The Linnean Nerita is a 

 \ery good genus, and there is nothing 

 in the general character of any of the 

 species, which can perplex even a 

 young student. We think it tends ra- 

 ther to retard than to advance the pro- 

 gress of the science, to construct new 

 genera, where there are not strong 

 motives for doing so. 



In Turton's Linne 76 species of 

 Nerites are described; and eight 

 species have been found indigenous to 

 Britain. 



Genus 31st.~IIALIOTIS. Ani- 



