TROCHUS TOP SHELL. 101 



TROCHUS Perspective* 

 STAIRCASE TROCHUS. 



Specific character. Shell conical, obtusely 

 marginated at the base ; umbilicated; the um-^ 

 bilicus large, funnel-shaped, round which the 

 whorls wind spirally, having a crenated margin ; 

 aperture nearly quadrangular ; shell flat under- 

 neath, longitudinally and transversely striated ; 

 colour greyish, beautifully variegated with och- 

 rous brown spots. 



Inhabits the shores of Asia : frequent about 

 Alexandria. 



TROCHUS Conrfiyliophorus. 

 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. 



A singular fact in the natural history of this 

 shell is, that it accumulates, during its formation, 

 different foreign substances, and is often found 

 covered with stones, coral, small shells, and 

 fragments of shells ; on account of this curious 

 property, it has acquired the name of the Carrier, 

 It has not been ascertained how this animal, 



* Plate IV. figure 5. 



f Imbricated, tiled, from the Latin imbrex, a tile 



9* 



