OF THE UNITED STATES. 235 



CER1THIUM, Brug. 

 Species. 



C. *dislocatum. Shell attenuated, acute at the 

 apex; volutions with numerous, minute, revolving 

 impressed lines, and from fifteen to eighteen trans- 

 verse, elevated costa to each volution, which are dis- 

 located near the summit of each volution hy a revolv- 

 ing line, as deeply impressed as the suture. 



Length one and one-fourth of an inch. 



Inhabits the coast of the United States. 



Cabinet of the Academy and Philadelphia Mu 

 seum. 



This shell is very common on the southern shores, 

 particularly on that of East Florida, but I have also 

 found specimens on the shore of Maryland. Lister 

 tab. 979, fig. 36, represents a shell very similar to 

 this, but larger. 



The effect of the impressed line, which revolves 

 above the middle of the volutions, is, to separate the 

 longitudinal raised lines into two series, whereof the 

 lines of the superior series, are much shorter and 

 thicker than the others. 



