REVIEW OF OLD AND NEW STANDARDS OF PLEISTOCENE DIVISION 425 



Tracing these four shorelines beyond the Mediterranean to the Atlantic 

 coast, Deperet remarks (1918.2) that observers have hitherto noted the 

 height of the locality of marine fossil beds without looking for the altitude 

 of the corresponding shoreline, which in many instances is far above the 

 fossil beds. Four corresponding shorelines, however, are determinable 

 on the Atlantic coast — Gibraltar, Portugal, Morocco, Senegal, and 

 Angola — from observations of Deperet, Choffat, Dollfus, Dereims, Chu- 

 deau, and Chautard, which in Deperet's opinion may be coordinated 

 respectively with the 



(4) Monastirian Stage (18-20 meters), 



(3) Tyrrhenian Stage (28-30 meters), 



(2) Milazzian Stage (55-60 meters), 



(1) Sicilian Stage (90-100 meters). 



Observations extended northward along the French Atlantic coast 

 convince Deperet (1918.3) that as far north as Brittany the Quaternary 

 sea also occupied successively four shorelines of 90-100 meters, 55-60 

 meters, 30-35 meters, and 18-20 meters above the present shoreline, 

 which coincide exactly with his Sicilian, Milazzian, Tyrrhenian, and 

 Monastirian shorelines of the Mediterranean. This northern coast also 

 shows traces of old shores characterized by shells at some quite low 

 levels — the first at 7-10 meters, the second at 18-20 meters, above the 

 present ocean level. It will appear natural to attach the 20-meter level, 

 as noted above, to the Monastirian Stage. At that time the geography of 

 our coasts was nearly identical to the present geography. 



Marine Quaternary of the French and English Atlantic Coasts 



Deperet continues (1918.4) that along the French and British coasts 

 of the English Channel are observed marine deposits 6 meters above the 

 present mean sealevel, containing Buccinum grcenlandicum, but the alti- 

 tude of the corresponding shoreline is not determined. 



In the valley of the Somme, where the Quaternary sea penetrated to 

 Abbeville (the locality famous for the earliest Chellean industry), are 

 observed the marine depositions of Menchecourt and Mautort (Prestwich, 

 1860, and subsequently described by Charles Lyell, d'Ault du Mesnil, 

 Ladriere, Eutot, and Common t, famous archeologists). The base of the 

 marine deposit of Menchecourt is only 5 meters above the high waters of 

 the Somme; its summit about 11 meters; above which are clays with a 

 minimum altitude of 15 meters, constituting a terrace of the 18-20-meter 

 level belonging to Deperet's Monastirian Stage, with which the author 

 correlates the cold marine terrestrial fauna described below. In these 

 beds occur the fluvial species Corbicula flwninalis, surviving from the 



