1849.] HAMILTON ON THE GEOLOGY OF ASIA MINOR. 363 



Devonian, and then doubts the existence of fossils on the Giant's 

 Mountain opposite to Therapia. In answer to the first objection, I 

 have only to say that they have been described by Mr. Strickland 

 in the 5th vol. of .the Transactions of the Society, where a list of the 

 fossils is given on the authority of Mr. James Sowerby. I might also 

 observe, that the mineralogical character of the rock, so closely resem- 

 bling that of some of the argillaceous schists of the Lower Silurian 

 rocks as exhibited in North Wales, is also a justification of their 

 having been so named at a time when the Devonian system was un- 

 known*. 



With regard to the existence of fossils on the Giant's Mountain, I 

 also appeal to Mr. Strickland, and at the same time I can assure the 

 Society that every one of the specimens we have exhibited came from 

 that locality and from near the summit of the hill ; indeed, we ob- 

 tained the best in situ, from the fresh-cut side of a new road which 

 was then in process of construction. We also found the same forma- 

 tion on the European side of the Bosphorus between Therapia and 

 Constantinople, but no other locality afforded so many fossils. On 

 a subsequent occasion too, I had an opportunity of ascertaining that 

 the hill of Boulgourlou behind Scutari consists mainly of the same 

 formation, interstratified with beds of quartz rock, probably altered 

 sandstone ; here also I found a few imperfect traces of organic remains. 

 With regard to what M. Tchihatcheff says, of no one else having 

 since been able to detect these palseozoic fossils on the Giant's Moun- 

 tain, Mr. Strickland has already well remarked, that although the 

 geology of this mountain has been noticed with more or less exactness 

 by Andreossy, Fontanier, and the author of the ^ Sketches of Turkey,' 

 not one of them has noticed its numerous and interesting fossils. 



The only other point I have to notice respecting the neighbour- 

 hood of Constantinople, is the statement of M. Tchihatcheff, that 

 "Mr. Hamilton and others have marked as cretaceous the northern 

 shore of the Nicomedian Gulf," whereas the Devonian system is, as he 

 says, there clearly displayed. As I did not visit the Nicomedian Gulf 

 either by land or by water, I never have or could have ventured to pro- 

 nounce an opininion as to whether the northern shore of the gulf was 

 Devonian or cretaceous. 



And here it is to be observed, that by reference to the last edition 

 of the Map of Russia published by Sir R. Murchison, in which the 

 geological structure of the neighbourhood of Constantinople is laid 

 dow^i from the best authorities he could then refer to, it will be seen 

 that the north side of the Gulf of Nicomedia is coloured as palaeozoic, 

 and therefore the proposal of M. Tchihatcheff to erase the cretaceous 

 rocks, which were partially inserted in the first edition of that Map 

 (but not on my authority), has long since been anticipated. Finally, 

 as to whether these palseozoic rocks be Silurian or Devonian it is not 

 for me to pronounce. It is possible that both formations may there 

 be found to exist, and in calling these Silurian, Mr. Strickland and 

 myself were simply guided by the best opinions we could then obtain ; 



* See Bulletin de la Societe Geologique de France, vol. viii. p. 268, *' Notice Geo- 

 logique sur les en\irons de Constantinople, par M. de Verneuil." 



VOL. V. PART I. 2 C 



