564 MR K. BULLEN NEWTON ON SOME CRETACEOUS BRACHIOPODA 



and gently arched, with markedly straight and oblique lateral margins diverging 



from a fairly narrow and tapering summit region to the rounded and expansive 



base. Numerous concentric growth striations cover the surface, the more 



prominent of which are more or less equidistantly arranged. On the dorsal 



aspect of the specimen is seen the remains of an apparently large foramen, the 



details of which, on account of fracture, are too obscure for description. The 



microscopically punctate character of the Terebratulidse is well displayed in the 



test of this specimen. 



Dimensions (ventral valve). — 



Length ...... 37 mm. 



Width . . . . . . 34 „ 



Diameter . . . . . . 12 ,, 



This is a very variable species. The Angola specimen compares favourably 

 with the more elongate examples from the type locality of Tour nay in Belgium 

 which occur in the " Tourtia " beds, regarded as of Cenomanian age. Excellent 

 figures have been published of the species, Lamarck's type specimen having been 

 drawn by Davidson, while d'Archiac has issued illustrations and descriptions of 

 examples from Belgium under the name of T. nerviensis. The specimen gives no 

 indication of folds or plications, being perfectly smooth ; hence it differs from both 

 T. biplicata and T. dutempleana, which are recorded in the lists of Cretaceous 

 fossils from northern areas of Africa. 



Distribution. — The later studies of Davidson have demonstrated that the 

 species had its origin in Aptian times, having been found at Faringdon, Upware, 

 Shanklin, and other English localities. In the present case the species may be 

 considered as of older Cenomanian or Vraconnian age, since it is associated with 

 fragmentary Ammonites indicating the zone of Schloenbachia injiata. 



Occurrence. — In a limestone similar to that associated with Neithea tricostata, 

 exhibiting minute specks of mica and glauconitic grains. 



Locality. — No. 295 — N.E. of Lobito Bay. 



PELECYPODA. 



Fam. OstreidjE. 



Exogyra cf. jiabellata, Goldfuss. (PL II, fig. 1.) 



Exogyra Jiabellata, Goldfuss: Petrifacta Germanize, 1833, vol. ii, pi. lxxxvii, fig. 6, p. 32. 



Ostrea flahella and Jiabellata, Orbigny : Pat. Frangaise: Terr. Cretaces Lamellibi anchia, 1846, vol. iii, 



pi. 475, p. 717. 

 Exogyra Jiabellata, Pervinquiere : Etudes Pal: Tunisienne : Gast. Lametlib. Cretaces, 1912, pi. xiii, figs. 6-8, 



p. 189. 



Remarks. — The collection contains a fragmentary pair of valves in the closed 

 condition which may apparently be referred to an exogyriform oyster probably 



