358 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [May 26, 



and others in the ' Memoires' and ' Bulletin' of the French Geological 

 Society. The fine work of Deshayes is the standard for the organic 

 remains *, and for general descriptions and details the works of Cuvier 

 and Brongniart. 



Taking the numher of described Calcaire grossier species at a 

 moderate estimate of 600, I can only, after carefully excluding all the 

 Barton and Bracklesham fossils, determine the following 20 as occur- 

 ring also in the London clay of the I^ondon district f : 

 Anomia lineata, Sow. (A. striata, Desh.) Pecten corneus, Sow. ? 

 Beloptera belemnitoidea ??, Blainv. Pseudoliva obtusa, Sow. ? 



Cassidaria carinata, Desh. Rostellaria macroptera ?, Lam. 



Fusus bulbiformis, Lam. Sigaretus canaliculatus, Sow. 



Infundibulum trochiforme, Sow. (Ca- Solarium canaliculatum, Lam. 



lyptrsea trochiformis, Desh.) patulum, Sow. (? patulum oi 



Globulus depressus, Sow. ? Desh.) 



Natica glaucinoides, Sow. Triton viperinus, Desh. 



Nucula similis, Sow. (N. margaritacea, Teredo personata ?, Lam, 



Lam.) Turritella irabricataria, Desh. 



minima, Sow. ? sulcifera. Lam. ? 



Ostrea flabellula, Lam. 



Thus it appears that not quite four per cent, of Testacea of the 

 Calcaire grossier are found in the London clay of London : and even 

 this small number is of httle chronological value ; for, with few ex- 

 ceptions, all these species have a wide vertical range in the Eocene 

 series of France, twelve of them descending to the "Sables inferieurs 

 et Lits coquilliers,'^ and several of them ranging upwards to the " Gres 

 de Beauckamp," and scarcely any of them being of characteristic Cal- 

 caire grossier species J. (See the works of Deshayes and D'Archiac.) 



In the general character of the Testacea of the London clay and 

 Calcaire grossier, the differences observable are as great as in the 

 species. Thus in the former. Cephalopoda, Phytophagous Gastero- 

 poda, and Lamellibranchiate Dimyaria preponderate ; and in the latter, 

 Zoophagous Gasteropoda and Lamellibranchiate Monomyaria. 



If we compare the fishes, the plants, the Foraminifera, the Crus- 

 tacea, and the Zoophytes of the London clay and Calcaire grossier, the 

 same marked distinctions between them are traceable throughout. 

 The Calcaire grossier abounds in Foraminifera, and possesses many 

 Zoophytes. The former are almost unknown, and the latter very 

 scarce, in the London clay, which however exhibits fine groups of 

 Fishes^, Reptiles and Crustacea, together with a Flora \\ of remark- 

 able variety and beauty, whilst in the Calcaire grossier ^ such fossils 



* Coquilles Fossiles des Environs de Paris. 



t Future comparisons of the organic remains will, no doubt, considerably modify 

 this list. 



J This can only, from the want of revised lists and more complete descriptions, 

 be a rough approximate estimate. An exact value must not be attached to it. 



§ Agassiz's Report on the Fossil Fishes of the London Clay. — Reports of the 

 Brit. Association for 1843 and 1844. 



II Bovi^erbank, Fossil Fruits of the London Clay. 



•li A local case will exemplify the general bearing. 



Foraminifera. Zoophjrtes. Fishes. Reptiles. Crustacea. Plants. 

 CaZe. g-ross. dep.de l'Aisne(D'Ar.) 45 1,5 1 2 



London clay (Morris, Brit. Foss.) 1 3 53 l6 4 107 



The number of undescribed species of London clay Crustacea is very considerable. 

 Alex. Brongniart enumerates thirteen species of plants from the Calcaire grossier, 

 and Agassiz but 12 species of fishes. 



