532 PBOCEEDINGS OF THE GEOLOGICAL SOCIETY. [June 25, 



characters of both tipper and lower molars of this small Iguanodon, 

 no one in quest of the truth of the matter could affirm " that the 

 teeth of this reptile were perfectly distinct from those of Iguanodon 

 Mantelli." In the last plate of Prof. Owen's ' Monograph' for the 

 forthcoming volume of the Palseontographical Society, the mandible 

 and mandibular teeth are figured ; and he had hoped to receive a 

 proof to show to the Meeting. The mandibular teeth exhibited 

 by Mr. Hulke were identical with those previously discovered by 

 Mr. Fox. In the ' Monograph ' the evidence will be found of the 

 specific, but not generic, distinction of Mr. Fox's small Dinosaur 

 from the large Iguanodon Mantelli. 



4. On the Glacial Phenomena of the Long Island or Outee Hebeldes. 

 By James Geikie, Esq., F.B.S.E., of H.M. Geological Survey of 

 Scotland. 



Fiest Papee. 



I. Introduction. 



The detailed observations of the Geological Survey having led my 

 colleagues and myself to conclude that the great mer de glace which 

 enveloped the south of Scotland during the intensest cold of the 

 Glacial Epoch was so extensive as entirely to fill up the basin of the 

 Clyde, and all the sea between Ailsa Craig and the mainland, I 

 became curious to ascertain what the islands of the Outer Hebrides 

 had to tell us in regard to the extension of the old ice-sheet in that 

 direction. My brother had in 1865 shown that the island of 

 Bute was glaciated from end to end by the ice that streamed out- 

 wards from the mountain-glens of Argyllshire ; and subsequent ob- 

 servations by myself in Ayrshire had proved that the rocky coasts 

 between Lendalfoot and Glen App were striated in a direction 

 parallel to the shore-line by glacier masses which flowed south- 

 west upon what is now the bed of the sea. My colleague, Mr. D. 

 R. Irvine, had also found that ice from the southern uplands had 

 swept across the Binns of Galloway from the interior of the country 

 — the whole coast between Portpatrick and Corsill Point exhibiting 

 numerous rock-striations and glaciated surfaces, whose prevailing 

 direction is towards south-west. Thus it would appear that an 

 immense mass of glacier ice, derived partly from the Highlands and 

 partly from the Southern Uplands, set towards the north coast of 

 Ireland. Moreover the position of the strise and the whole character 

 of the glaciation of that south-west part of Scotland induces the 

 belief that the Scottish mer de glace became confluent with that of 

 Ireland, splitting upon the northern coasts of Galway and flowing 

 south into what is now the Irish Sea, and west into the Atlantic. 

 But to what extent that ice-sheet stretched seaward, it would be 

 premature at present to offer even a conjecture. That we shall yet 

 be able to form some approximately true estimate of the depth and 

 breadth of the mer de glace can hardly be doubted. Towards this 

 end, it obviously becomes important to trace the direction of 



