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SUPPLEMENT TO THE BRITISH 



I am very much inclined to believe that T. Cantabridgiensis should be considered 

 specifically distinct from T. depressa and its varieties. It occurs in the Lower Greensand 

 at Upware, but not so abundantly as T. depressa. It is also possible that T. cyrta may 

 require to be detached from the last-named species. 



49. Terebratula Robertoni, D'ArcMac. Dav., Cret. Mon., PL IX, fig. 25 ; and 



Sup., PI. V, fig. 26. 



A shell much resembling D'Archiac's species occurs at Faringdon, and likewise, 

 according to Mr. Meyer, at Godalming ; but there prevails still much uncertainty relative 

 to the value of the species, and until more abundant material is procured this identification 

 will require to be considered provisional. 



50. Terebratula Moutoniana, var., TSOrb. ? Sup., PI. IV, figs. 11 — 13. 



Terebratula Moutoniana, B'Orb. Terr. Crdt., pi. 510, figs. 1 — 5, 1847. 



— — W. A. Ooster. Pet. remarquables des Alpes Suisses, p. 20, 



pi. iv, figs. 19—21; pi. v, figs. 5—12; 

 and pi. viii, figs. G — 8, 1863. 



— — Schloenbach. Zeitschr. Deutschen geolog. Gesellschaft, 



1866. 



— — Walker. Geol. Mag., vol. v, p. 403, pi. xviii, fig. 6, 1868 



(non Waldheimia Moutoniana,!) 'Orb., Lan- 

 kester, Geologist, vol. vi, p. 414, pi. xxi, 

 figs. 1—3, 1863). 



— — Pictet. Melanges Paleontologiques, 2nd liv., p. 103, 



pi. xxv, figs. 1—4, 1867. 



Spec. Char. Oval, elongated, widest about the middle, slightly truncated in front. 

 Ventral valve uniformly convex, without sinus, much arched in profile ; beak not much 

 produced, slightly incurved and truncated by a largish foramen, separated from the 

 hinge-line by a wide and narrow deltidium in one piece ; beak-ridges inconspicuous. 

 Dorsal valve convex, with a rounded mesial fold and lateral depressions. Surface smooth, 

 marked only by concentric lines of growth. Loop short and simple, not as wide as that 

 of T. sella. 



Length 1 inch 5 lines, width 11, depth 10 lines. 

 Obs. Although there exists in this species an appreciable mesial fold in the dorsal 

 valve of many specimens, no corresponding sinus or depression is present in the ventral 

 one. It varies, however, a good deal, while some French and Swiss examples attain 

 larger dimensions than they do in Great Britain, and are comparatively broader. 



