Vol. 58. ] IN EUROPEAN TURKEY. 161 
Prof. Sertry desired that the Author should state the physical 
evidence on which he inferred the former great development of the 
freshwater lake assumed to be represented by the Sea of Marmora. 
The genus Dreissena was met with in the marine Miocene of 
France, and Neritina was separated by so uncertain a boundary 
from the marine Nerita, that the paleontological evidence was not 
conclusive that freshwater conditions had given place to marine 
in the way stated. The change was not improbable, but it 
needed demonstration. It did not appear evident to the speaker 
that the rhyolitic outbursts could be determined as of definite 
geological age: they pierce indeed the Nummulitic Series, but there 
was need of local evidence to fix their age. 
Mr. H. W. Burrows remarked that the assemblage of fossils was 
not very convincing, as to either exclusively marine or exclusively 
freshwater conditions ; and they might well be of fluvio-marine 
origin. The presence of foraminifera, however, would be distinctive, 
and he therefore recommended microscopic examination of the 
specimens. 
The AvurHor replied that he thought that the occurrence of 
marine Miocene (Helvetian) shell-beds at Erekli on the Gulf of 
Xeros required a much greater change in the position of the coast- 
line of the Miocene A®gean land, than Prof. Sollas seemed in- 
clined to admit. The displacement would not be less than 100 
miles from the line shown in Lapparent’s ‘ Traité de Géologie.’ 
The Author had quite recently examined the Quaternary shell- 
beds at Gallipoli, referred to by Prof. Sollas, of which a sketch- 
section was given in Calvert & Neumayr’s paper.’ This section is 
described in their paper as composed of eroded remains of Tertiary 
beds, tilted and dipping inland, overlain by the horizontal shell-beds 
to a depth of 30 or 40 feet, the latter forming steep cliffs towards 
the Hellespont. 
The Quaternary beds examined by the Author form a very solid 
shell-conglomerate, with horizontal partings, split vertically in 
many places into columnar masses, and protected from further 
erosion by a talus of their own material in large tabular blocks, 
extending in places for 100 feet into the water. ‘These blocks are 
generally tilted, so as to present the appearance of an inland dip, 
but no older material is at present visible. In any case, the Author 
did not think that these shell-beds materially affected the question 
of the erosion of the Dardanelles, as they did not make up more 
than a twentieth part of the height of the cliff-sections visible in 
the channel. He also thought that the deposition of these shell- 
beds was subsequent to the erosion of the channel, as Calvert & 
Neumayr stated that out of 33 species of shells occurring in 
them, 29 were still living in the Mediterranean, generally widely 
spread. 
The Author quite admitted the fact pointed out by Prof. Seeley, 
1 «Die jungen Ablagerungen am Hellespont,’ Denkschr. k. Akad. Wissensch. 
Wien, vol. xl (1880) pp. 357-78 & 2 plates. 
Q.J.G.8. No. 229. M 
