96 



2. The mountains N. of Ben-Nevis are chiefly mica-slate : S.E. of 

 Loch Lochy this rock passes into gneiss ; on the sides of Glen Gloy, 

 Glen Tuntick, and Glen Roy, it contains garnets, and alternates with 

 quartz rock; in the valley of the Spean it is interstratified with 

 granular limestone. 



Felspar, porphyry, and greenstone occur, in the mica-slate, in Glen 

 Gloy, in Glen Roy, at Caldivan, and in the valley of the Spean. 



The S. shore of Glen-Nevis, near Ballahulish, is a granitic aggregate 

 of felspar and mica ; with concretions of mica and hornblende : granite 

 occupies the low ground; gneiss succeeds, passing eastward, in to mica- 

 slate and clay-slate, in which are beds of roof-slate alternating with, 

 and traversed by, greenstone dykes, and interstratified with granular 

 limestone. 



In Glen Coe mica-slate is cut through obliquely by compact felspar- 

 porphyry ; in the bed of the river is a fine-grained granite, with con- 

 cretions like those of Ballahulish ; the granite is succeeded by gneiss 

 at a lower level, and at a higher, by compact felspar, speckled and 

 veined with epidote. 



3. On the Isle of Sky the authors offer the following observations : 

 The syenite lies upon the hyperstene rock ; the passage into which 



is not gradual, but abrupt ; the hyperstene rock passes into compact 

 greenstone, and often skirts the syenitic mountains ; the lias rests on 

 syenite, or forms detached outliers ; and this observation holds good 

 invariably. 



. There is no such thing as a vein of syenite in the lias. The trans- 

 mutation of lias into white granular and compact limestone is more 

 constant at its junction with syenite, than Vvith greenstone or trap ; 

 in the latter case it sometimes varies, sometimes not, — a circumstance 

 difficult to account for. 



The hyperstene rock seldom adjoins the lias ; when it does, like 

 greenstone or trap, it both intersects and covers it. 



Although the authors make a distinction between the rocks of 

 syenite and those of trap and hyperstene, on account of their position 

 relatively to the stratified rocks, they do not ascribe to the former a 

 higher antiquity than to the latter ; for the syenite must be the pro- 

 duction of a later sera than the lias, since it has materially altered it. 



Feb. 6th. — A Paper was read, " On the discovery of a new species 

 of Pterodactyle ; and also of the Faeces of the Ichthyosaurus ; and of a 

 black substance resembling Sepia, or Indian Ink, in the Lias at Lyme 

 Regis ; " — by the Rev. W. Buckland, D.D. F.R.S. Professor of Mine, 

 ralogy and Geology in the University of Oxford. 



1. — This specimen of Pterodactyle was discovered, in December 

 last, by Miss Mary Anning, and was found to belong to a new species 

 of that extinct genus, hitherto recognized only in the lithographic 

 Jura-limestone of Sollenhofen, — which the author considers as nearly 

 coeval with the English chalk. 



The head of this new species is wanting, but the rest of the ske- 

 leton, though dislocated, is nearly entire ; and the length of the claws 

 so much exceeds that of the claws of the Pterodactylus-longirostris 

 and brevirostris, of which the only two known specimens are mi- 



