TROCHUS TOP SHELL. 101 



that they feed upon vegetables ; the shell has 

 neither notch nor canal, and the mollusk no 

 siphon. 



TROCHUS Perspective* 



STAIRCASE TROCHUS. 



Specific Character. Shell conical ; umbilica- 

 ted ; the umbilicus large, funnel-shaped, round 

 which the whorls wind spirally, having a cre- 

 nated margin; aperture nearly quadrangular; 

 shell flat underneath, longitudinally and trans- 

 versely striated ; colour greyish, beautifully 

 variegated with ochrous brown spots. 



This shell is the type of the modern genus 

 Solarium. It inhabits the shores of Asia : fre- 

 quent about Alexandria. 



TROCHUS Cvnchyliopkorus. 



CARRIER TROCHUS. 



Specific Character. Shell conical, coarse, 

 obtusely plaited ; whorls imbricated,! base con- 

 cave ; colour brownish white ; size an inch and a 

 half long, and an inch and three quarters broad. 



It is a singular fact in the natural history of 



* Plate IV. figure 5. 

 t Imbricated, tiled, from the Latin imbrex, a tile. 



