276 



POPULAR CONCHOLOGY. 



formerly very rare (specimens having been sold 

 for one hundred guineas), but are now more 

 common : they are seldom perfect. 



140. Atlanta. — Shell, somewhat resem- 

 bling the Carinaria, c ^^ ) 

 but having the apex ///^ 

 spirally whorled; trans- 

 parent, and large 

 enough to contain the 

 animal entirely : a thin 

 and glassy operculum. 

 Animal, head having two tentacula, and large 

 eyes at the base ; foot or fin large. — 2 species 

 recent. 



This genus is found in all the seas of hot 

 climates. 



141. Pterotrachea. 1 __ , „ 

 , nr, .. No shell. 



142. Phylliroe. J 



In these two genera, the animal resembles 

 the Carinaria in the position of the heart and 

 gills; they are both found in the Mediterra- 

 nean, and, owing to their extraordinary trans- 

 parency, it is very difficult to perceive them 

 when in the water. The Pterotrachea has four 

 species, the Phylliroe only one. 



