44 BRITISH OOLITIC AND LIASIC BRACHIOPODA. 



and strong ; at other times numerous and more delicate, commencing at the umbo and 

 beak, becoming gradually and regularly wider as they approach the front ; generally, in 

 the young state, the plaits are divided towards the margin, and while placing these into 

 another species, (T.furcata,) Mr. Sowerby states, "it is therefore possible these maybe 

 only young of orbicularis." In adult specimens it is rare to see the plaits bifurcated, 

 but as a proof that it is sometimes so, we have figured Plate XII, fig. 15, a remarkable 

 specimen, found by M. Deslongchamps, wherein the plaits are once and even twice 

 divided ; we are also indebted to M. Deslongchamps for the fine specimen illustrating the 

 loop. Professor King, in his ' Monograph of Permian Fossils,' proposed to separate this 

 species from the genus Terebratula, under the generic title of Eudesia, but in the 

 Appendix seems disposed to cancel the genus, as it possesses all the characters of true 

 Terebratula. Ter. cardium does not vary to the extent of most species, and is always 

 recognisable ; it is found abundantly in the Great Oolite of Bath, Cirencester, &c, and in 

 beds of similar age at Boulogne-sur-mer, Caen, &c. ; it was never found in the Lias of 

 Weston, as stated by Mr. Sowerby, and subsequently by other authors, but it seems 

 confined to a narrow vertical range, and to be characteristic of the Great Oolite. 



39. Terebratula Buckmanii, Bav. Plate VII, figs. 15, 16. 



Diagnosis. Shell irregular, oval, longer than wide ; valves convex, smooth, minutely 

 punctuated ; beak small, truncated by a large entire foramen, almost touching the umbo ; 

 deltidium small, concealed ; lateral ridges indistinct ; margin line curved, rising in front. 

 Length 18, breadth 11, depth 8 lines. 



Obs. This species occurs in the Inferior Oolite of Winchcombe, near Cheltenham, 

 where it was found by Professor Buckman, Dr. Wright, and others. It is quite distinct 

 from T. ornithocephala by its shape, form of beak, foramen, and hinge marginal line of 

 valves. We likewise find in the smaller valve of some specimens a central longitudinal 

 elevation, extending from the umbo to the front, from which the two remaining lateral 

 portions of the valve recede rather abruptly, as may be seen in fig. 16. PI. VII, figs. 15, 

 16, from Prof. Buckman's Collection. 



40. Terebratula Lycettii, Bav. Plate VII, figs. 17 — 22. 



Biagnosis. Shell more or less circular ; small, valves convex ; beak rounded, trun- 

 cated by an almost emarginate foramen ; the deltidium in two pieces, touching only in one 

 point above the umbo ; lateral ridges indistinct ; marginal line slightly curved ; surface 

 smooth, finely punctuated. Length 8, width 7, depth 4 lines. 



Obs. This small species was found by Mr. Moore in the upper Lias of Barrington, 

 near Ilminster, where it abounds, and varies in size from 1 to 8 lines in length, but does 

 not appear to attain longer dimensions. 



