﻿Bulletin 2 1 136 



in having three instead of two eolumellar plaits, and in its pro- 

 portionally broader form. But in other respects the earlier, 

 Chipola, species shows the characters of its Pliocene descendant. 



Mitra Barnardensis, n. s. 

 PL IV, fig. 9. 



Shell with tip eroded, remeining whorls eight ; suture dis- 

 tinct ; transverse sculpture of sharply-defined riblets of which 

 there are about twelve on the last whorl. These riblets extend 

 from suture to suture and over three-quarters of the body-whorl. 

 Spiral sculpture of grooves channelled in the interspaces between 

 the riblets, and of about seven unequal threads on the canal ; 

 aperture na'row ; columella with four plaits of which the two an- 

 terior are much less prominent ; outer lip lirate within. Length 

 of shell 13 ; greatest width 4.5 mm. 



Chipola marls, Bailey's Ferry, Florida. 



Cornell University collection. 



Mitra scopuli, n. s. 

 PI. IV, fig. 10. 

 A species closely related to Mitra Barnardensis occurs in the 

 lower bed (Oligocene) of Alum Bluff, Florida. This species 

 differs from the Chipola shell in its broader, shorter form and 

 more convex whorls. Length of decollate shell 11.5 ; greatest 

 width 5 mm. 



Cornell University collection. 



Mitra Myttonis, n. s. 

 PL V, fig. 1. 



Shell small, slender, fusiform, whorls six ; nuclear smooth ; 

 subsequent whorls sculptured with nearly straight transverse ribs 

 and fine spiral grooves in the interspaces ; penultimate whorl- 

 with fifteen ribs ; body-whorl almost smooth over its latter third 

 or half as the ribs become obsolete ; outer lip lirate within ; 

 columella with three well-marked plaits. 



Length of largest specimen 5 ; of last whorl 3 ; of aperture 

 1 .5; greatest width 1.5 mm. 



