206 MESSES, p. r. KENDALL AND E. G. EELL ON 



we cannot offer any adequate explanation of such extreme size, it 

 is worthy of note. 



The remarkable character of the fauna appears to point to certain 

 conclusions of great moment, and, with the reservations stated at the 

 outset, we venture to bring them forward in the hope that the 

 criticism to which they will doubtless be subjected will, whether 

 favourable or otherwise, give us a secure standpoint from which to 

 view the great mass of additional esridence which will assuredly be 

 brought to light when the deposit is submitted to a closer and more 

 exhaustive examination. 



Taken as a piece of negative evidence, the southern facies of the 

 fauna may be inferred from the total absence of the boreal or arctic 

 forms of predatory MoUusca. 



Of such shells as Fusus antiquus, F. gracilis, Buccinum Dalei, 

 and B. undatum, which are so common in the Eed Crag, no trace 

 has been found. Turritellce and other shells have been found to 

 be bored by carnivorous Gastropods, but the abundance of the large 

 Nassa serrata will account satisfactorily for this circumstance. 



We think, however, that this absence indicates the prevalence of 

 physical conditions in the British area and "Western Europe gene- 

 rally very different from those now obtaining. 



If a comparison be made between the fauna of those few Upper 

 Tertiary beds which have been noticed in the Channel and the West 

 of England, and is further carried onward to include the Pliocene 

 beds of the Cotentin in France, it will be found that the Medi- 

 terranean element is a conspicuous feature, the whole having a 

 southern character with a manifest exclusion of E,ed Crag and 

 strictly boreal shells. The beds of the Cotentin have been worked 

 by MM. Gustavo DoUfus and Yasseur, and through the kind- 

 ness of the former gentleman we have received a more complete 

 list of the fossils of that region than is usually obtainable ; and 

 though they appear to us to be of an earlier date than the St. Erth 

 clay (probabl}^ being of Coralline-Crag age), they approximate suffi- 

 ciently closely to admit of their inclusion in the same statement. 



Even in the most recent of the deposits mentioned, viz. that at 

 Selsey, the Fusi before alluded to are entirely absent, and even in 

 recent times they are rare at the western end of the Channel. 



The Mediterranean aspect of the fauna down the western sea- 

 board of France in Mio-Pliocene times has long been noticed ; but no 

 special significance was attached to it in consequence of the 

 proximity of the Spanish province, which has no really distinctive 

 fauna, but merely a blending of northern and southern forms, and 

 during a warmer period the former element might easily have been 

 excluded by climatal unsuitability. 



W^e have shown, however, that the St. Erth deposit was probably 

 accumulated during the earlier portion of the Red Crag period, 

 when the premonitory refrigeration of the Glacial epoch had gone 

 on so far as to permit of a great descent of Boreal or even Arctic 

 MoUusca ; and in the oldest Red-Crag deposit, that of Walton-on-the- 

 Naze, 30 species occur which have an exclusively northern range in 



