256 MESSES. G. W. LAMPLUGR AND J. F. WALKER ON [May I903, 



Dimensions : — length of large valve = 32 millimetres ; length 

 of smaller valve = 19 mm. ; breadth = 12 mm. ; thickness = 7*5 mm. 



In a smaller globose specimen the length of the large valve = 

 22-5 mm.; length of smaller valve = 13 mm.; breadth = 8'5 mm.; 

 thickness = 9 mm. 



Tekebratella Menardi, Lamarck, var. pterygotos, nobis. (PI. XVIII, 

 figs. Sa-3c.) 



1819. Terebratella Menardii, Lamarck, ' Hist. Nat. des Anim. sans Vert.' vol. vi, 

 pt. i, p. 256. See Davidson, Ann. & Mag. Nat, Hist. ser. 2, vol. v (1850) 

 p. 445 & pi. xiv, tig. 50. 

 1829. Terebratula truneata, J. Sowerby, 'Min. Conch.' vol. vi, p. 71 & pl.dxxxvii, 



fig. 3. 

 1834. Terebratula Menardi, L. von Bucli, 'Ueber Terebrateln ' p. 78 & pi. iii, fig. 42. 

 1839. Terebratula Menardi, L. von Bucli, Mem. Soc. Geol. France, vol. iii, p. 184 



& pi. xvii, fig. 6. 

 1841. Terebratula canal icnlata, Fr. A. Roemer, ' Versteinerungen des Nord- 



deutschen Kreidegebirges ' p. 41 & pi. vii, fig. 12. 

 1847. Terebratella Menardi, A. d'Orbigny, ' Pal. Franc. Terr. Cret,' vol. iv, p. 118 



& pi. dxvii, figs. 1-15. 

 1852. Terebratella Menardi, Davidson, ' Brit. Cret. Brachiop.' Monogr. Pal. Soc. 



p. 24 & pi. iii, figs. 34-42. 

 1868. Terebratella Menardi, Scbloenbach, in Benecke's Geogn.-Paliiont. Beitrage, 



vol. i, p. 458 & pi. xxii, fig. 2. 

 1872. Terebratella Menardi, Geinitz, ' Elbtbalgebirge ' p. 157 & pi. xxxvi, figs. 



37-38. 

 1874. Terebratella Menardi, Davidson, ' Brit. Cret. Brachiop.' Suppl. Monogr. 



Pal. Soc. p. 24 & pi. viii, fig. 14. 

 1878. Terebratella Menardi, Deicke, 'Die Brachiop. der Tourtia von Mvilheim ' 



p. 18 & (pi.) fig. 9. 

 1884. Terebratella Menardi, Davidson, 'Brit. Cret. Brachiop.' App. to Suppl. 



(vol. v) Monogr. Pal. Soc. p. 247 & pi. xviii, fig. 6. 



We have found very few specimens of Terebratella Menardi var. 

 at Shenley. They differ from the Faringdon shells in being- 

 larger and wider ; the variety resembles some of the specimens from 

 the Cenomanian of Le Mans (France), but differs from these by the 

 wing-like expansion of the hinge-line. We have not sufficient 

 material to determine whether it should be regarded as a distinct 

 species. Davidson, in his Supplement to the ' British Cretaceous 

 Brachiopoda,' states that the only difference that he can perceive 

 between T. truneata and T. Menardi is that the Lamarckian species 

 is rather longer and a little more transverse ; its ribs are likewise 

 somewhat sharper. Our shells are also remarkable for the great 

 thickening of the front-margin. 



Terebratella Menardi occurs in the Cenomanian of Devon and in 

 the Chloritic Marl of Chardstock. In France it is found at several 

 localities, especially at Le Mans in the Cenomanian. In Germany 

 it occurs near Dresden, and at Essen {T. canaliculata, Roemer). It 

 occurs near Tournay (Belgium) in the Tourtia. We consider the 

 Shenley form to be nearer the Tourtia specimens than to those 

 from the Aptian of Faringdon. A single specimen of a variety of 

 T. Menardi has been found at Upware ; it also occurs at Brickhill. 



Dimensions of a shell with thickened front-margin : — length = 

 17 millimetres ; breadth = 18 mm. ; thickness = 10*5 mm. 



