566 



J. E. BLAKE ON THE UPPER 



in the lumachelle. These beds form the O x of M. Pellat, and 

 the middle of JSTos. 15-17 of M. Hebert. They are seen at the top 

 of the cliff east of Gris Nez with the usual Astarte. Above these 

 the beds become softer and more glauconitic by degrees, the lowest 

 being a very fossiliferous band with Lima boloniensis, over which is 

 about 48 feet of clays, the upper half of which is more sandy and 

 full of hard bands, and forms a better cliff, the limit upwards being 

 drawn where the sandy clays cease to be glauconitic and to have a 

 blue tint. Lithologically these beds have a very close resemblance 

 to the upper portion of the Kimmeridge Clay of Chapman's Pool, 

 which likewise becomes more glauconitic, and passes gradually into 

 Portland sands, and thence to the Flinty series. The fossils here 

 noted were, in addition to the Lima mentioned, Ammonites pseu- 

 dogigas, Belemnites Souichii, Pleurotomaria Rozeti, Myacites jurassi, 

 Astarte Scemanni, Trigonia concentrica? , Mytilus unguiculatus, Pecten 

 lamellosus?, P. Morini, Perna Boucharcli, Avicula octavia, Plicatula 

 Boisdini, Ostrea expansa, 0. hruntrutana, Acrosalenia Koenigi, Ci- 

 daris boloniensis, and Serpula triserrata. 



The highest beds of the series (P v P 2 , P 3 of M. Pellat) are only 

 seen in the cliffs on either side of Wimereux to the north, and of 

 Portel to the south. The base consists of about 9 feet of sand and 

 sandstone with fucoidal markings, like the flinty beds of St. Albans ; 

 and these contain abundance of large Cardium Pellati, and some 

 Trigonia gibbosa and other shells closely imbedded. Above is a 

 shell-bed crowded with Serpula gordialis, just as happens at Port- 

 land and St. Albans. Natica ceres and many small Cerithia are 

 here abundant. The succeeding rocks are more calcareous repeti- 

 tions of the same kind, all the hard parts being fair limestones, and 

 the softer quite sandy, making a total of about 15 feet. The lime- 

 stones are exceedingly fossiliferous, having yielded M. Pellat nearly 

 70 species; but the whole remains of the same character as the 

 Flinty Series of St. Albans, though in the latter case the sands have 

 been consolidated into flints. The other most noticeable fossils 

 appear to be Ammonites bononiensis, Natica elegans, de Lor., Ceri- 

 tliium Manseli (near the top), C. pseudo-excavatuml ', C. septempli- 

 catum, Pleurotomaria Rozeti, Trigonia incurva, T. Carrei, Astarte 

 rugosa, Corbicella Pellati (?=Sowerbya Dukei [cast]), Cardium 

 dissimile, Pecten lamellosas, and Echinobrissus Brodiei. The over- 

 lying strata are of very peculiar character, being mostly composed 

 of calcareous rubble and tuff, in which there are scarcely any recog- 

 nizable fossils ; and such as are recorded (Astarte socialis, Cypris, 

 Cyrena Tombecki, &c.) are not known in English Portland rocks. 

 The irregular manner in which these lie, with ferruginous beds 

 intercalated in places, according to M. Pellat, forbid us to look upon 

 them as certainly equivalent to the Portland building-stones, which, 

 as a lithological group, or as a palseontological horizon containing 

 Ammonites giganteus (true), Buccinum naticoides, B. angulatum, and 

 Cerithium portlandicum, are not here to be found. There is, in fact, 

 no proof that any thing but Wealden beds overlie the Flinty Series at 

 Boulogne. 



