122 



costfe, and fine revolving lines: whorls 15, slightly con- 

 vex; ribs clivided and somewhat dislocated by an im- 

 pressed line below the suture; color purplish black ; 

 within the same. 



The described specimen is morc than 7* of 'in iiich 

 long, but the usual size is less than Y^ au mch. 



Cerithium protextum Conr. Proc. Acad. Pliilad. 

 1846. Feb. p. 26. 

 Hab. Tampa Bay. 



* 290. Cerithium dislocatum Say. 



„Sh. attenuated, acute at the apex; volutions with 

 minute, revolving impressed lines, and from 15 — ^18 

 transverse, elevated costas to each volution, Avhicli are 

 dislocated near the summit of each volution by a re- 

 volving line, as deeply impressed as the suture." 



Long. IV4 inch. 



Cerithium dislocatum Say Journ. Ac. Sc. Philad. 

 2. 1821. p. 234. 



Cerithium dislocatum Conrad Sillim. Journ. I. 1846. 

 p. 405. 



Cerithium dislocatum Holmes ib. VII. 1849. p. 157. 

 Hab. Very common particularly on the coast o£ East 

 Florida, but I have also found specimens on the shore 

 of Maryland. (Say.) 



„List. tab. 979 f. 36 (Terebra) is very similar but 

 larger. The effect of the impressed line, which revolves 

 above the middle of the volutions is, to separate the 

 longitudinal raised lines into tv^o series, where of the 

 lines of the superior series, are much shorter and thik- 

 ker than the others. 



* Cerithium megasoma C. B. Ad. 



Sh. long ovate conic: mostly brownish or reddish 

 black, white within the aperture; thick, with three small 

 Spiral rather minutely granulous ridges, of which the 

 Upper two are larger and more distant, and interme- 



