A. J. Jukes-Browne — Division of Upper Chalk. 163 



man. He finds that a terrace 30 metres above the bed of the river is 

 covered with a sequence of gravels, sands, and the younger Loess 

 which, contain a fauna including Elephas antiquus. Hippopotamus, 

 Horse, and the ancestor of ^. primigenius. Along with these 

 remains implements of Chelles type are found in abundance. Another 

 terrace, 20 metres below this, is overlain by similar deposits, 

 but the Palaeolithic implements contained in these are later and 

 include late Chelles (Chelleen evolue) and St. Acheul types. Both 

 these terraces are covered with a younger Loess full of implements of 

 Le Moustier type. 



Penck & Briickner^ consider that the younger Loess (Le Moustier) 

 passes under the moraines of the fourth glacial episode. They thus 

 agree with the conclusions of Professor Commont, but differ from him 

 and fi'om Professors Boule and Obermaier in placing the St. Acheul 

 period in the second interglacial period. Professor Boule speaks of 

 the discovery of St. Acheul palaeoliths in the moraines of the third 

 glacial episode ; and Obermaier records them from the 55 metres 

 terrace of the River Garonne, which he correlates with moraines of 

 the third glacial episode. 



These conclusions are shown in the subjoined table, where they are 

 compared with the evidence derived from a study of the Palseolithic 

 and glacial deposits of the southern parts of Great Britain. A very 

 close agreement is seen to obtain among the European deposits of 

 different localities, associated with the remains of Palseolithic man : 

 an agreement which strengthens the evidence as to the age of the 

 raised beaches of Southern England and Wales. 



IV. — The Division of the Upper Chalk. 

 By A. J. Jukes-Browne, F.R.S., F.G.S. 

 TTIHE Geological Magazine for February contained a lengthy 

 I criticism by Mr. E,. M. Brydone of my article on the B,ecognition 

 of Two Stages in the Upper Chalk, in the volume for last year. It is 

 certainly curious that he should set himself the task of adverse 

 criticism in such a voluminous fashion when he acknowledges at the 

 outset that he sympathizes with my proposal. It appears, however, 

 that he is dissatisfied with my reference to his work, and that he 

 doubts the reliabilitj^ of my lists of fossils from the new zones of 

 Ojfaster pilula and Actinocamax quadratus. 



The first is a personal question, and the facts are these : While 

 I was collecting information about the zones of the Upper Chalk in 

 Germany and France, Mr. Brydone wrote to me (October 3, 1911) 

 saying that he proposed to make a new zone in Hampshire and 

 Sussex by separating the lower part of the old zone of A. quadratus 

 under a new name, and retaining a restricted zone of A. quadratus for 

 the upper part. He and Mr. Griffith had already divided the old zone 

 into three subzones, and he proposed to unite the two lower subzones 

 into a zone of 0. filula^ asking if I approved the use of that fossil 

 as an index in spite of its being very rare in the lowest beds. 



■' Die Al'^en im Eiszeitalter , vol. i, jp. 112, 1901-9. 



