﻿STROPHOSTYLUS. 197 



IV. Family. — Velutinidte, Gray, 1840. 

 1. Genus. — Strophostylus, Hall, 1879. 



This genus or sub-genus is separated from Platyostoma by having a twisted 

 columella and by not being umbilicated. It belongs to the Upper Silurian and the 

 Devonian formations. 



The shell described below is referred to it with much hesitation, because it 

 seems, as far as can be judged from the defective state of the specimens, to 

 resemble the shells placed under this genus by Hall and by CEhlert. 



1. Strophostylus, sp. PI. XIX, figs. 11, 11 a. 



? 1870. Natica, sp., Tietze. Dev. Schicht. Ebersdorf, p. 41, pi. ii, figs. 27, 27 a. 



Description. — Shell rather large, spiral, of few volutions, subglobose. Spire 

 small, low, flattened above. Suture small and deep. "Whorls less than half 

 exposed, very convex on the shoulder, less convex on the back. Surface smooth. 

 Body-whorl large and voluminous. Shell-structure thick. 



Size. — Height 15 mm., width 24 mm., but the measured specimen is probably 

 crushed and distorted. 



Locality. — There are two specimens in the Lee Collection in the British 

 Museum, labelled " Lummaton," but their mineral character is so different from 

 the generality of Lummaton fossils that I have little doubt that there is some 

 error, and that they came from another locality, possibly from Chircombe Bridge. 

 Though I have introduced them here, they must certainly be excluded from the 

 Lummaton list. 



Remarks. — This species seems most probably to belong to the genus Stropho- 

 stylus ; but, the aperture of both specimens being obliterated and the shape 

 contorted, it is almost impossible to make any positive generic identification. 



Affinities. — It appears to be a more definitely coiled shell than Strophostylus 

 Cheloti, (Ehlert. 1 



It is very similar to Platyostoma Giebeli, Kayser, 2 but its spire is higher and 

 is more distinctly coiled. 



1 1887, (Ehlert, ' Bull. Soc. d'Etud. Sci. d'Angers,' p. 6, pi. vi, figs. 8—8 d. 



2 1878, Kayser, ' Abhandl. Geol. Specialk. Preuss.,' Band ii, pt. 4, p. 99, pi. xvi, figs. 1—3. 



