﻿135 Florida Oligocene Shells 17 



are very feeble, the anterior more oblique and stronger. 



Length of shell 4.5 ; greatest width 3 mm. 



Oligocene of the Oak Grove sands, Santa Rosa County, 

 Florida. 



Cornell University and Mr. Aldrich's collection. 



Caricella Isabella, n. s. 

 PI. IV, fig. 7. 

 Shell of moderate size, thick and strong, whorls six, ex- 

 clusive of the eroded nucleus ; suture distinct. Sculpture consis- 

 ting only of numerous longitudinal striations. Columella with 

 four plaits ; canal short ; reflexed. Length of shell 27 ; of aper- 

 ture and canal 18 ; greatest width 14 mm, 

 Chipola marls, Bailey's Ferry, Florida. 

 Cornell University collection. 



Perplicaria prior, 11. s. 

 PI. IV, fig. 8. 



Shell with five whorls ; nucleus consisting of a whorl and a 

 half, smooth to the unaided eye but showing under the lens three 

 revolving threads ; sculpture of the remaining whorls cancellate 

 due to the intersections of the spirals (of which there are on the 

 body whorl fifteen strong and an equal number of fine alternating 

 threads) with obliquely transverse costae ; suture distinct ; outer 

 lip with a submarginal varix, lirate within along the entire length 

 but more sharply so towards the base ; columella with three plaits, 

 that nearest the base being nearly horizontal and denticulate, the 

 second very oblique, and the uppermost slightly oblique ; pillar 

 glazed with a slight callus. 



Length of shell 14 ; greatest width 6 mm. 



Chipola marls, Bailey's Ferry, Florida. 



Cornell University collection. 



This interesting shell is the second species of the genus 

 Perplicaria Dall yet described. The type of the genus, P. per- 

 plexa from the Caloosahatchie Pliocene was described by Dr. Dall 

 in 1890. The Chipola shell resembles closely that species but 

 differs from it in possessing much more oblique transverse costse, 



