AT ST. ERTH, NEAR LAjSTD's E2fD, COJclNWALL. 69 



(for none of the many peculiarly tropical genera that occur in the 

 Miocene are present in it) we seem to have evidence of a Pliocene 

 age for the bed, and, I think, on the whole, a preponderance in 

 favour of IS'ewer, rather than Older Pliocene. The relation of the 

 fauna is more in the direction of the Italian Pliocene than in that 

 of the Pliocene of Xorth-western Europe. 



At the outset of my investigations I thought it likely that the 

 bed would prove to belong to that very late part of the i^^ewer Plio- 

 cene period called now Quaternary, when the small submergence 

 took place which I have, in my memoir on that period in England *, 

 traced as having preceded the minor Glaciation, and to which I have 

 referred the Cyrena-ioimaition^ and with which the rich bed of 

 marine Mollusca at Selsey in Sussex is connected. This Selsey bed 

 contains some species of Mollusca which now live only to the south 

 of the British shores, though, like its species in the marine beds coeval 

 with it, from Essex northwards over the east side of England, which 

 present no such southern indications, these are all living species ; 

 and I thought that as the difference in this respect between these 

 beds, thus coeval with the Selsey one, is evidently due to the presence, 

 during their accumulation, of an isthmus connecting the South-east 

 of England with the continent, which prevented the water which 

 had access to Sussex from the Atlantic having any access to the 

 North Sea, except round the jN'orth of Scotland, the more westerly 

 position of the Land's End might be the reason for the still more 

 southern aspect of the St. Erth Mollusca ; but the species I after- 

 wards got together comprised so many not known from Selsey, and, 

 withal, some known only in the fossil state, that this view became 

 untenable. We must therefore seek a more ancient period to which, to 

 refer it ; and as between the Selsey bed and the Eed Crag we have only 

 beds belonging to successive stages of the submergence that accom- 

 panied the great glaciation of England, in all of which the Arctic 

 aspect is apparent more or less in the moUuscan remains they yield, 

 though much the most marked in the earlier of those beds, such as 

 Bridlington, there is nothing, until we go back to the Eed Crag, with 

 which we can connect it in point of age ; and then the evidence of 

 connexion is more inferential than direct, because the geographical 

 connexion of the St. Erth bed is clearly more in the direction of the 

 Pliocene of Southern Europe than of the Phocene of the area washed 

 by the JN'orth Sea. One only of the six St. Erth Nassce, viz. N, 

 granulata (or granifera), is known from the !N"orth-Sea Crag, while 

 three of them seem to me identical with Italian Pliocene forms, 

 and the other two belong to a group (the mutabilis group) that is 

 peculiar to the south of Europe, both fossil and recent. 



Our knowledge of the Normandy-Crag Mollusca is very hmited. 

 Of the specimens from the older part of it, the " Conglomerat a 

 Terebratules " (which in its physical character, and in the species of 

 Biryozoa it yields, seems to have the closest affinity with the Coralline 

 Crag), scarce anything but a few casts of indeterminate species are 

 given by Messrs YieiUard and DoUfus, in their " Etude Geologique 

 * Quart. Journ. Geol. Soc. vol. xrsviii. p. 732. 



