24 



BRITISH CRETACEOUS BRACHIOPODA. 



Plate II, figs. 7, 8. Two remarkable malformations, in the Collection of Mr. C. B. Rose, 

 from Letheringsett, West Norfolk, 

 figs. 9, 10, 11. Elongated varieties, in the Collection of the Rev. T. Image, 

 fig. 12'. Interior of smaller valve. 

 a. The socket walls. 



i. The sockets where the teeth, j, in the larger valve articulate. 

 f. Extremity of the septum. 

 c. Lower pair of riband-shaped lamella. 

 e — e'. Upper or anchor-shaped pair, 

 fig. 12". Illustrates a profile view or section of the interior of both valves, 



the septum is seen to touch the larger valve at the point k. 

 fig. 12 a . Interior of larger valve illustrated. 



fig. 33. From a remarkable malformation from the Sussex Chalk, in the 

 Collection of Mr. Catt; this unique specimen varying so much 

 from the common type, exhibits three marked stoppages of 

 growth. 



Genus — Terebratella, I)' Orb. 1847. 



Animal attached to submarine bodies by the means of a pedicle issuing from the 

 beak of larger valve. Shell inequivalve, elongated, or transverse, variable in shape ; valves 

 convex ; structure punctuated, smooth, or variously striated and plaited ; beak truncated 

 by a foramen of an oval or irregularly triangular shape, placed more under than above 

 the summit ; deltideura in two pieces, disunited in many cases, the aperture being 

 completed by a small portion of the umbo; cardinal area more or less defined; loop 

 (to which are affixed the arms) doubly attached, proceeding from the crura, but 

 before attaining its greatest length, it gives off a flat, wide, more or less horizontal 

 process, likewise attached to a central longitudinal, more or less elevated septum, the 

 principal lamella proceeding till it doubles itself in the shape of a loop, as in true 

 Terebratulae. 



Obs. I am only acquainted with two certain species of British Cretaceous Tere- 

 bratella ; it is possible that there may exist one or two more, but which, until future 

 discoveries, I have left under the genus Terebratula. 



8. Terebratella Menardi, Lamarck, Sp. Plate III, figs. 34 — 42. 



Terebratula Menardi, Lamarck. 1819. An. sans Vert., vol. vi, p. 256, No. 50. 



— — Parkinson. An Introduction to the Study of Org. Remains, 



p. 227, 1822. 



— — Defrance. 1828. Die. des Sc. Nat., vol. liii, p. 160. 



