GASTROPODA— TURRITELLIDJE. 



735 



436. T. exaltata Conrad. (Fig. 1069, c.) Miocenic. 



Slender like the preceding, with strongly carinate angle over- 

 hanging ; shoulder concave with faint spirals, one near suture. 



Chesapeake (Calvert) formation of Maryland, etc. 



Fig. 1069. 



a, Turritella variabilis ; 6, T. cumberlandia 

 Martin, Md. Surv. ) 



T. exaltata. (After 



437. T. subannulata Heilprin. (Fig. 1071, c) 



Oligocenic-Pliocenic. 



Main angulation at the center of whorl pronounced, whorls flat 

 and sloping above, vertical below to the second carina, after which 

 the whorl rounds downward ; whorls embracing nearly to the 

 second carina ; a strong spiral above suture. 



Abundant in Caloosahatchie marls of Florida, and the Wacca- 

 maw beds of Carolina. Also in the Chipolan beds (Oligocenic) of 

 Florida. 



438. T. perattenuata Heilprin. (Fig. 107 1, a.) Pliocenic. 

 Very long and slender, whorls deeply concave in the middle, a 



