376 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [May 26, 



we can reason upon this fact, we require a more extensive determina- 

 tion of the organic remains * . 



We have before (ante, p. 358) shown that the London clay, so far 

 from presenting the same large proportions of forms common to the 

 Calcaire grossier, at present shows only about four per cent, of French 

 analogues. 



It is in the beds, therefore, of Bracklesham and Barton, and not 

 in those of Bognor or London, that we have the approximate repre- 

 sentatives in time of the middle and lower Calcaire grossier. The 

 London clay itself is most probably, as I have before stated the 

 Bognor beds to be, of the age of some of the subdivisions of the group 

 of "Sables inferieurs" of M. d'Archiac, — possibly near the posi- 

 tion of the Lits Coquilliers ; but its exact parallel in this series can- 

 not at present be clearly determined. At all events, the fossils of 

 the Lits Coquilliers present a greater analogy to those of the London 

 clay than do those of the Calcaire grossier. Still the number of 

 species common to the two deposits is only about 33 ; or if we take 

 the number of species found in the Lits Coquillie?^s and Sables infe- 

 rieurs at 200, the proportion will be but sixteen and a half per cent, 

 on that number. The following is a list of themf : — 



Anomia lineata, Sow. Cardium semistriatum ?, Desk, 



Cassidaria carinata, Sow. Solarium canaliculatum, Lam. 



Conus concinnus, Sow. Nucula similis, Sow. 



(bicoronatus, Mell.) (raargaritacea, Lam.) 



Cytherea tenuistriata> Sow. ? Pectunculus pulvinatus, Lam. 



(obliqua, Desk.) (? P. brevirostris, Sow.) 



Fusus porrectus, Sow. Panopaea intermedia, Sow. 



(uniearinatus, Desk.) (Corbula dubia, Desk.) 



bulbiformis. Pholadomya margaritacea, Sow. 



angusticostatus, Mell. Pinna affinis, Sow. 



regularis, Sow. (margaritacea, Lain.) 



Globulus sigaretinus, Sow. Pleurotoma colon, Sow. 

 (Natica sigaretina, Bef.) elegans, Mell. 



Infundibulum trochiforme, Sow. Pseudoliva semicostata, Sow. 



(Calyptrsea trochiformis, Desk.) (Buccinum semicostatum, Desk.) 



Murex spinulosus, Desk. Pyrula tricostata, Desk. 



Natica glaucinoides, Sow. Ringicula turgida, Sow. 



(labellata, Lam.) (Auricula ringens, Lam.) 



Nautilus zic-zac, Sow. Sigaretus caualiculatus, Sow. 



Corbula striata, Lam. Teredo personata, Lam. 



Rostellaria macroptera, Lam. Turritella imbricataria, Lam. 



Ostrea tiabellula, Lam. Venericardia Suessonensis, d'Archiac. 



As in " London clay," Foraminifera and Zoophytes are compara- 

 tively scarce in the " Lits Coquilliers," whilst remains of Reptiles are 

 not uncommon. 



* The more exact relations of these two divisions will be discussed in the next 

 paper. 



f It is to be observed, however, that if we confine ourselves to a comparison of 

 these fossils of the Lits Coquilliers with the fossils of the London clay at the inter- 

 mediate geographical position of Hampshire, we shall find the analogy much 

 stronger. Thus, out of the 42 Hampshire species, 26 are analogues of the Lits 

 Coquilliers. But the difficulty is, that although this typical Hampshire fauna 

 ranges on the one side into the Paris system, and on the other into the London 

 system, yet it becomes respectively associated in each case with faunas in other 

 respects dissimilar. At the same time we have good geological horizons both 

 above and below, restricting to within tolerably narrow limits the superposition 



