OP CONCHOLOGY. 81 



wet when the tide recedes ; some few 

 of them live in very deep water. 



Lamarck and Latrellie have made a 

 new genus from the Trochi of Linne, 

 under the name of Pyramidella ; the 

 generic character of which is opening, 

 entire, and semi-oval, pillar projecting 

 and raised with three transverse folds, 

 perforated at the base as in the Tro- 

 chus Dolabratus of Linne. The above 

 writers have formed two other genera, 

 Salarium and Monodonta. The Tro- 

 chus perspectives, or what is called 

 the Staincase Trochus in England, 

 illustrates the first ; and Trochus La- 

 bio the second. 



In Turton's Linne 133 species are 

 described ; and twelve have been 

 found on the British coasts, including 

 one species found on the mountains of 

 Cumberland. 



Genus 28th.— TURBO. Animal a 

 Limax ; shell univalve, spiral, and so- 

 lid ; aperture contracted, orbicular, 



