438 



ture. The conglomerates are composed of angular fragments of tra- 

 chyte, imbedded in a tufaceous paste. The inclosed portions are some- 

 times softer than the cement, when the rock assumes a honeycomb 

 appearance, but they are more often harder, and stand out in bold 

 relief. The conglomerates rest upon and alternate with the trachyte, 

 and in some places are intersected by basaltic dykes. Veins of car- 

 nelian and chalcedony are stated to be contained in the igneous rocks, 

 and near Filbornou to pass through the conglomerate, traversing both 

 the basis and the included fragments. These conglomerates are 

 considered by Mr. Strickland to have been accumulated by water, and 

 the contained fragments, though commonly angular, are sometimes 

 rounded, and included in finely laminated volcanic sand. On the 

 Asiatic side of the Bosphorus the igneous rocks commence en masse 

 at Kavak, under the old Genoese Castle, and extend to Yoom-bornou 

 on the Black sea, or perhaps further ; and on the European side they 

 commence on the north of Buyukdere, and also extend to the Black 

 sea. Besides these great masses of igneous products, trachytic and 

 trap dykes were observed by the authors traversing the Silurian rocks 

 at Baltalimani, in the hills above Bebek, at Kiretch-bornou, and the 

 base of the Giant's Mountain. 



3. The Tertiary deposit commences immediately on the west of 

 Constantinople, and extends inland about three miles, till it meets the 

 transition formations, and ranges along the north coast of the Sea of 

 Marmora for many miles, its western limit being at present undefined. 

 Id is best exhibited in the quarries at Baloukli and Makri-kuei, where 

 it consists of horizontal beds of soft, white, shelly limestones and marls, 

 resting on sand in which no fossils have been observed. Near Con- 

 stantinople the deposit was apparently accumulated in an estuary, 

 for it contains a species of Cardium, and considerable numbers of a 

 fossil considered to be a Cytherea, the whole being associated with 

 land and freshwater shells, some of which resemble recent species. 



Along the banks of the Bosphorus the authors observed no traces 

 of a tertiary formation ; and consequently infer that this channel was 

 opened at a comparatively very recent period. 



The only ancient alluvium mentioned in the memoir is an extensive 

 and thick deposit of ferruginous clay, sand, gravel and boulders, rest- 

 ing upon the Silurian or transition rocks. It commences a few miles 

 north of Constantinople, forms the subsoil of the Forest of Belgrade, 

 and apparently skirts the southern side of the Lesser Balcan range. 



December 14. — William Percival Hunter, Esq., of the Albany; 

 Francis Charles Parry, Esq., of the Court of Bankruptcy ; Major Wil- 

 liam Harding, of Ilfracomb, Devonshire ; John Hey, Esq., Curator of 

 the Leeds Philosophical Society j William Stanger, Esq., of Wisbeach, 

 Cambridgeshire; William Charles Henry, M.D.,F.R.S., Manchester j 

 William Gray, jun., Esq., of York ; James Thompson, Esq., of Kirk- 

 house, near Brampton, Carlisle; the Hon. Henry Upton, of White- 

 hall Place ; William Darley Hull, Esq., of the Wood House, Ross- 

 trevorj Ireland; Thomas Cabbell^Esq., Barrister at Law, Essex Court, 



