74 BRITISH OOLITIC AND LIASIC BRACHIOPODA. 



a later period, Baron Von Buch distinguished the shell above described from B. spinosa, 1 

 and applied to it the name of senticosa, which I have adopted for the present form to avoid 

 the introduction of another appellation for the species under notice. It is also, probable, 

 that Zieten's Ter. spinosa 2 may belong to the present form, as it does not seem to present 

 the characters of the true spinosa, and although both of these species are somewhat allied, 

 they should always be considered as distinct, B. senticosa being a much more transverse 

 and more depressed shell ; the beak is smaller, and the surface ornamented by a greater 

 number of slender spines, while in B. spinosa the shell is more spherical, the beak rounded 

 and more recurved, the surface being also not only spinose but plaited. Both species 

 seem to occur in the same localities, viz., in the lowest beds of the Inferior Oolite of 

 Dinnington and Burton Radstock, where they were collected by Mr. Moore. On the Conti- 

 nent, it is common in beds of the same age, at Curcy, Moutiers, &c, in Normandy, and is 

 likewise stated to occur at Grumbach, near Amberg, by Baron Von Buch, in the 

 inferior Oolite beds above the Lias. M. D'Orbigny does not seem to have noticed this 

 species in the Inferior Oolite (T. Bajoceanf where the type commonly occurs, but places 

 it in the Oxford Clay, 4 where, according to MM. Bouchard and Moreau, the species is 

 likewise found in the Departement de l'Yonne ; I have not, however, had the advantage of 

 seeing any of those specimens, but from M. D'Orbigny referring to Baron Von Buch, 

 and giving his locality Grumbach, it is probable that it is the same species; none, however, 

 have yet been noticed in our English Oxford Clay. 



67. Rhynchonella ringens, Herault, Sp. Plate XIV, figs. 13, 14, 15, 16. 



Terebratula grimace, Herault. 



— ringens, V. Buch, 1834. Uber Terebrateln ; et Mem. de la Soc. Geol. 



de France, 1838, vol. iii, Ire ser., pi. xiv, fig. 3. 



— — Deshayes, 1836. Nouv. ed. de Lamarck, p. 312, No. 65. 



— — Bronn, 1848. Index Pal., p. 1249. 

 Rhynchonella ringens, D'Orb., 1849. Prodrome, vol. i, p. 258. 



Diagnosis. Shell remarkably shaped, the depth exceeding the width and length ; the 

 smaller valve rises suddenly from the umbo to the front by an almost perpendicular convex 

 curve, forming a large rounded central plait or elevated mesial fold, bent downwards at its 

 extremity, which lies over to meet the sinus of the perforated valve ; on either side of 

 the mesial fold three or four smaller lateral plaits form a regular curve from near the 

 umbo to the margin. In larger valve, the beak is small, acute, and not much recurved; 

 the foramen is entirely surrounded by the deltidial plates, but not remarkably separated from 



1 Uber Terebrateln, 1834, vol. vii, 1813. 



2 Zieten Wurtemb. Verst., p. 44, fig. 1, 1832. 



3 Prodrome, vol. i, p. 286. 



4 lb., p. 375. 



