﻿248 DEVONIAN FAUNA. 



for distinguishing them from the American species described as Euomphalus 

 Hecate by Hall, whose description, however, is rather vague in one or two 

 particulars. 



Affinities. — This shell has much the appearance of a small or young variety of 

 Euomphalus circularis, Phillips, but it quite differs from it in the shape of its 

 whorls, and in the almost entire absence of any depression round the suture. 



Euomphalus Dionysii, Montfort, is distinguished by its more elevated spire, 

 and its more numerous, circular, and more slowly increasing whorls. In Euom- 

 phalus Igevis, var. turritus, Sandberger, which appears to me distinct from Eu. 

 laevis, and probably a variety of Eu. Dionysii, the spire is still more elevated. 



Straparollus grandis, de Koninck, 1 is a very much larger form, and its whorls 

 are rather fewer and more horizontally flattened. 



3. Euomphalus circularis, Phillips. PI. XXIV, figs. 9, 10. 



1840. Euomphalus circularis, Phillips. Pal. Foss., p. 94, pi. xxxvi, fig. 171. 



1854. — Morris. Cat. Brit. Foss., p. 247. 



1888. — — Etheridge. Foss. Brit., vol. i, Pal., p. 163. 



Description. — Shell very large, spiral, turrited, very depressed, so as to be 

 almost lenticular, of three or four volutions. Spire very low, loosely and rather 

 irregularly coiled. Suture shallow, obtuse. Whorls subquadrate or subcircular ; 

 after rising slightly close to the suture spreading out flatly to the shoulder, where 

 they turn through a blunt angle and become gently and uniformly convex on the 

 back, at the bottom of which they turn through a still greater angle, which 

 bounds the base. Base flat or slightly convex, sloping inwards, forming a 

 narrow border round the wide, deep umbilicus, which is marked within by a 

 sharp, deep, sutural, spiral trench or excavation. Mouth (or section of whorl) 

 subquadrate or subcircular. Shell-structure rather thin. 



Size. — Height 30, width 52 mm. 



Localities. — From Wolborough there are three examples in Mr. Vicary's 

 Collection, three in the British Museum, and several in the Museum of Practical 

 Geology. There are four specimens in the Torquay Museum, two of which seem 

 to have come from Lummaton and two from Wolborough. There is a very large 

 specimen from Lummaton, showing the umbilical side, in the Woodwardian 

 Museum, and another in my Collection. 



Remarks. — Phillips's type of this species is in the Museum of Practical Geology, 

 but at the time that the specimens for figuring were selected we had not recog- 



1 1881, de Koninck, ' Ann. Mus. Roy. H. N. Belg.,' vol. vi, p. 126, pi. xix, figs. 10, 11. 



