of a few Brachiopoda. 257 



while in other specimens one or two slight depressions correspond 

 to the undulations of the frontal margin. Another remarkable 

 feature is the sudden stoppage of growth visible in many speci- 

 mens, which has caused the remaining portion of the shell to 

 deviate from the regular line, forming a raised rim all round, 

 often presenting plaits not in existence before the sudden 

 stoppage of growth. It would likewise appear, on examination 

 of specimens collected by M. de Verneuil from several localities 

 in Spain, such as Maranchon, Anchueta, Villas del Covo, &c, 

 that this species first made its appearance in the Lias of that 

 country, although no authentic specimen has been to my know- 

 ledge found out of the Inferior Oolite, in France or in England. 



4. On Spanish Cretaceous Brachiopoda. 



In the British Museum are preserved two species of cretaceous 

 Brachiopoda from Santander, on the north coast of Spain, which 

 have not hitherto been noticed by any of the few authors who 

 have written on the fossils of that kingdom ; a short description 

 with figures may therefore not be devoid of interest. 



Terebratella Verxeuiliana, Dav. PI. XIV. fig. 4. 



Diagnosis. Shell inequivalve, circular, nearly as broad as long ; 

 valves nearly equally convex ; no distinct mesial fold or sinus ; 

 beak produced, with a short, flat, triangular area, wherein is 

 situated a large circular foramen, slightly indenting the beak, 

 but much more the area, completed and separated from the umbo 

 by a deltidium in two pieces ; valves ornamented by a few large 

 diverging costse, augmenting in number by the intercalation of 

 plaits at irregular distances from the beak and umbo, so that 

 round the margin from fifteen to seventeen unequal costae may 

 be counted on each valve; the plaits are intersected at variable 

 distances by well-marked concentric lines of growth. Structure 

 punctuated. Length 6, width 6^, depth 3 lines. 



Obs. Four specimens of this species are preserved in the British 

 Museum, all presenting the same characters. It is remarkable 

 for the few plaits that ornament its surface. It approaches most 

 in form to T. Moreana, D'Orb. (Pal. Tr. Ter. Cretacees, vol. iv. 

 p. 117. pi. 516. fig. 13-19), but does not seem to present the 

 mesial fold and sinus represented in M. D'Orbigny's figures of 

 that species ; the convexity of the valves in T. Vemeuiliana not 

 being interrupted by the projection of any of the plaits much 

 above the level of the others ; the position and dimensions of the 

 foramen are likewise different. 



Locality. The Upper Cretaceous beds of Santander, on the 

 north coast, of Spain. 



Plate XIV. fig. 4. Line showing the natural size ; fig. 4 a, h, r. enlarged 

 specimen in the British Museum. 



