Notices of Memoirs — G. F. Bollfus — Tertiary Seas. 475 



this sea was not very far off the eastern coast of Enghind ; the 

 other sea, the Western, or old Atlantic Sea, was off Ireland, pene- 

 trating in various gulfs into France, as in some part of Contentin, 

 Brittany, in the Loire valley, in the gulf of the Gironde, but there 

 was no way of communication with the Mediterranean basin crossing 

 France. In North Spain there are no Miocene deposits, in Portugal 

 Miocene beds are purely littoral. 



Tlie communication with the Mediterranean Sea was certainly by 

 the valley of the Guadalquivir. The Gibraltar Strait had not 

 exactly its present place. The fauna of these Miocene coasts was 

 warm and very similar to the existing fauna of Senegal and Guinea. 



We can divide Pliocene time into three periods, but the situations 

 of the seas were not very different. England was always in direct 

 continental communication with France; the English Channel was 

 not open at all All the Pliocene deposits of Belgium, North 

 France, or England, even the Lenham beds, are on the side of the 

 North-eastern Sea ; we find all these patches on the northern side 

 of the great anticlinal line of the Artois, Boulonnais, and Weald. 

 The fauna is different from the Miocene, and colder — it even turns 

 more and more cold during the progress of Pliocene time. Oa the 

 western or Atlantic side we have little gulfs leading the sea into the 

 land, but not so frequently and not so far as during Miocene times. 

 The Cornwall deposits, Contentin beds, and the Brittany patches 

 are very limited ; the basin of the Gironde contains no trace of 

 Pliocene beds, and we have no trace of recent marine beds at the 

 foot of the Pyrenees. In the north of Spain there is also no trace of 

 Pliocene beds. The continent seems to have been higher, and the 

 Atlantic tolerably distant. All the Portuguese sands recently dis- 

 covered are littoral, and only on the Algarve coast and south of 

 Spain do we find proof of the probable communication with the 

 Mediterranean. The Gibraltar Strait was not always in the same 

 place during Pliocene time; in the beginning probably the Guadal- 

 quivir valley to Murcia continued to be the strait, but later the rock 

 of Gibraltar was separated from Africa and a new road was open ; 

 this way was certainly deeper than the former one, and as deep as 

 the existing strait. By this depression the cold fauna of the depths 

 of the Atlantic penetrated into the Mediterranean Sea as far as Sicily 

 and Italy with Cijprina islandica. 



The geology of Morocco is unknown, but we have plenty of 

 information on Algeria. We have there great Miocene deposits 

 raised along the Atlas Chain up to a great altitude, and a little 

 lower a good and very long band of Pliocene beds of marine 

 and continental origin. Quaternary deposits, similarly continental 

 and littoral, occur lying along the actual coast, pointing out the 

 south side of the Mediterranean connection. 



In a few words, the English Channel has been opened very 

 recently, and no sea occupied its place before. No sea has crossed 

 France or Central Spain, and we are obliged to seek for an outlet 

 for the Eastern Sea during Miocene time by way of Germany, 

 Galicia,.and South Russia, or by tlie north of Scotland. 



During: the existence of the Pliocene seas there was no other 



