﻿149 Florida Oligocene Shells 31 



Length of shell 8.5 ; of aperture 2 ; greatest width 2 mm. 

 Chipola marls, Bailey's Ferry, Florida. 

 Cornell University collection. 



Niso Aldrichi, n. s. 

 PI. VIII, fig. 1. 



Shell small, smooth, polished and shining, conic, with a 

 rapidly tapering and acute spire ; whorls nine, the first three 

 slightly convex ; the following flattened. Shell without sculp- 

 ture. Suture distinct ; basal keel of the last whorl sharply de- 

 fined. 



Length of shell 4 ; greatest width 2 mm. 



Oak Grove, Santa Rosa County, Florida. 



Mr. Aldrich's collection. 



Symola trisintralirata , n. s. 

 PI. VIII, fig. 2. 



This species recalls S. attcnuata Dall of the Pliocene and 

 recent faunas but is larger with an additional whorl and with the 

 last whorl proportionally much shorter than in that species. 



Shell very slender, smooth, with seven flattened whorls 

 exclusive of the heterostrophic and fragmental nucleus, suture 

 very distinct ; aperture oval, with three lirse far within the shell ; 

 plait on the pillar strong and conspicuous. 



Length of shell 4 ; greatest diameter 1 mm. 



Oak Grove, Florida. 



Mr. Aldrich's collection. 



Astralium Dalli, n. s. 

 PI. VIII, fig. 3. 

 Shell small, depressed, trochiform, four-wliorled, with eight 

 slender spines at the periphery ; surface of the whorls coarsely 

 wrinkled just beneath the spines and finely wrinkled just above 

 the spines. Between these wrinkled bands are four faint spirals 

 generally seen only with a lens. Base rather flat with four or 

 five raised threads, either smooth or slightly beaded. 



