68 DEVONIAN FAUNA. 



1873. GoNiATiTES GLOBosrs, Kayser. Zeitschr. Deutach. Geol. Gesell., vol. xxv, 



p. 625. 

 1888. — — Etheridge. Brit. Foss., vol. i, Pal., p. 167. 



Description. — Shell small, sub-spherical, slightly flattened laterally and slightly 

 elliptic, of five or six whorls. Whorls increasing very slowly. Umbilicus from 

 one-half to one-third the diameter of the shell, wide, deep, and trochiform, with a 

 convex spiral ridge formed by the margins of the successive whorls. Sides short, 

 rising in a short convex wall round the umbilicus, then turning through a right 

 angle, and, after spreading almost flatly for a short distance, curving round to form 

 the bluntly angulated back. Suture-line with a large triangular front lobe, a deeply 

 concave front saddle of nearly the same width, a similar but rather smaller lateral 

 lobe, and a small concave lateral saddle. 



Size. — The specimen figured on Plate V measures 18 mm. long, 16 mm. wide, 

 and 11 mm. deep. 



Locality. — Wolborough. There are two specimens in the Torquay Museum 

 (Battersby Coll.), two in the British Museum, five in the Museum of Practical 

 Geology (Godwin-Austen Collection), and four in Mr. Vicary's Collection. 



Remarks. — The shells in the Torquay and Jermyn- Street Museums I carefully 

 compared, in company with Mr. Newton, with G. molaritis, and could trace no 

 such passage between them as was suggested by Phillips. At the same time we 

 find that both species are subject to considerable variation, especially in regard to 

 the size of the umbilicus. If, moreover, the rather doubtful specimen of G. molarius 

 in the British Museum, figured on Plate VI, truly belongs to that species, its 

 suture-line is very similar, difiering chiefly in the lobes and saddles not being so 

 deep as those of G. globosus, and thus it proves that they are closely allied 

 species. On a comparison of the Wolborough examples with Miinster's original 

 figures^ much doubt on the other hand must arise as to the correctness of Phillips's 

 identification. The German shells are decidedly deeper and have quite rounded 

 backs ; and the lobes of the suture-line are much more acute and much narrower 

 than the saddles, whereas in the British specimens they are apparently blunt, and 

 almost equal in size. I am inclined to the opinion that his identification cannot 

 stand, but in view of the extreme variability in the English shells, and the bare 

 possibility of their having to be regarded as a variety of G. molarius, I hardly like 

 to suggest a new name for them at present. 



From G. retrorsus umbilicatus, Sandb.,^ which Kayser regards as a synonym 



of G. globosus, the English shell is distinguished by the large size of the lobes 



compared with the saddles, in which respect Sandberger's shell is less like than is 



Miinster's. 



' 1832, Miinst., ' tJber Clym. und Gon. Fichtelgeb.,' p. 16, pi. iv, figs. 4 a—e. 



2 1851, Sandb., ' Verst. Ehein. Nassau,' p. 107, pi. x, fig. 1, and pi. x b, figs. 11 — 13. 



