﻿250 DEVONIAN FAUNA. 



Euomphalus Dionysii, Montfort, has a more elevated spire and less rapidly 

 increasing whorls. 



In Euomphalus trigonalis, Goldfuss, 1 the spire is lower, and there is a more 

 definite concavity on the upper part of the whorls near the suture, somewhat like 

 that seen in Sowerby's figure of his large specimen of Nerita speciosa, Sowerby. 2 



4. Euomphalus circularis, Phillips, var. gemmulifer, var. nov. PI. XXIV, fig 11. 



One of the specimens of Euomphalus circularis from Wolborough in the 

 British Museum is, as mentioned above, so different from the rest that I have 

 thought it best to distinguish it as a named variety. Possibly if further and 

 better specimens are found it may prove to be a distinct species. It is elliptically 

 coiled in about four volutions. Its spire, though conical, is so depressed that the 

 apex is decidedly below the plane through the shoulder of the body-whorl. The 

 section of the whorls is distinctly trigonal, the upper surface rising obliquely and 

 flatly to the shoulder, the back being moderately convex, and the base also flatly 

 oblique. Upon the shoulder is a prominent, elevated, rounded ridge or keel, 

 between two narrow concavities, which is divided into beads by numerous trans- 

 verse strise, visible only upon this keel. Upon the back are indications of several 

 fine spiral threads, rather closely arranged. The umbilicus is very large and 

 shallow. 



Affinities. — Euomphalus catilliformis, de Koninck, 3 is very similar to this shell, 

 but in it the raised keel is situated much lower down upon the whorl and further 

 from the suture than it is in the Devonian specimen. 



5. Euomphalus annulatus, Phillips. PL XXIV, figs. 6, 6 a. 



1841. Euomphalus annulatus, Phillips. Pal. Foss., p. 138, pi. 60, fig. 172*. 



1841. — annulosus, Phillips. Ibid., p. 231. 



1842. — annulatus, d' 'Arch, and de Vern. Geol. Trans., ser. 2, 



vol. vi, pt. 2, p. 363, pi. xxxiii, 

 figs. 11, 11 a. 

 1844. — — Ooldf. Petref. Genu., vol. v, p. 82, pi. clxxxix, 



fig. 9. 



1 1844, Goldfuss, ' Petref. Germ.,' vol. iii, p. 81, pi. clxxxix, figs. 5, 5 a. 



2 1840, Sowerby, ' Geol. Trans.,' ser. 2, vol. v, pt. 3, pi. lvii, fig. 15. 



3 1881, de Koninck, 'Ann. Mus. Koy. H. N. Belg.,' vol. vi. p. 146, pi. x, figs. 39—41. 



