64 BRITISH CRETACEOUS BRACHIOPODA. 



26. Terebratula sulcifera, {Morris). Plate VII, figs. 17 — 20. 



Tebebbatula sulcifera, Morris and Dav. Annals and Mag. of Nat. Hist., No. 133, 



vol. xx, p. 254, pi. xviii, fig. 7, 1847. 



— — B'Orbigny. Prodrome, vol. ii, p. 172, 1850. 



— — A Catalogue of the Terebratulae in the British Museum, p. 26, 



1853. 



Diagnosis. Shell obovate, oval or somewhat pentagonal and ventricose ; valves almost 

 equally convex ; beak short, thick rounded, moderately incurved, and truncated by a large 

 circular foramen ; deltidium partly concealed beneath the anterior portion of the aperture, 

 which overlies, and nearly touches the umbo of the dorsal or socket valve ; margins very 

 sinuous, externally ornamented by numerous concentric ridges of growth, regularly dis- 

 posed from the beak and umbo to the margin ; loop short and simple, not exceeding a 

 third of the length of the socket or dorsal valve. Dimensions variable. Length 22, 

 width 16, depth 16 lines. 



Obs. This species varies greatly in external aspect ; some examples (figs. 17 and 18) are 

 much inflated, while others (fig. 19) are more or less compressed, and somewhat triangular 

 in shape ; at times, the frontal line is almost straight, but in the generality of specimens 

 this portion of the ventral valve indents the opposite one ; the sulci are likewise more or 

 less produced, and regular. It is readily distinguished from Ter. semiglobosa, by the 

 large dimensions of its foramen, and from T. obesa, by its sulci, which are shorter and 

 more inflated in appearance. 



Ter. sulcifera occurs in the Lower Chalk of Cherry Hinton and Isleham, near 

 Cambridge ; at Hockwold, Norfolk, and in other localities. 



Plate VII, fig. 17. A very large, and fine example, discovered by Mr. Bunbury, figured in 

 the ' Annals and Mag. of Nat. Hist./ as the type of the species. 

 ,, figs. 18, 19, and 20. Other specimens from the Lower Chalk of the neigh- 



bourhood of Cambridge, in the collection of Mr. Morris. 



27. Terebratula semiglobosa, Sowerby. Plate VIII, figs 6 — 18. 



Terebeatula semiglobosa, Sowerby. Min. Con., vol. i. p. 48, tab. xv, fig. 9, 1813. 



— stjbundata, Sowerby. lb., p. 47, pi. xv, fig. 7, 1813. 



— subkotunda (part) Sow. lb., tab. xv, figs. 1-2, 1813. 



— stjbundata, W. Smith. Strata identified by organised fossils, p. 10, 



PI. iv, fig. 8, 1816. 



— — Lamarck. An. sans Vert., vol. vi, p. 248, No. 13, 1819. 



— semiglobosa., Lamarck. lb., p. 251, No. 27. 



— — and T. subundata, Parkinson. Trans. Geol. Soc, vol. v, 



1821. 



— — Mantell. Geol. of Sussex, p. 209, 1822. 



— — Brong. Env. de Paris, pi. ix, fig. 1, 1822. 



— — Fleming. A Hist, of British Animals, vol. i. p. 369, 1828. 



