T. F. Jamieson — the Scandinavian Glacier. 387 



indicated by the vascular grooves and impressions wbich mark the 

 surface of both plates and spines, except their bases, which were 

 evidently implanted in the thick skin. 



The peculiar group of extinct reptiles named by the writer the 

 Stegosauria, of which a typical example is represented in the present 

 restoration, are now so well known, that a more accurate estimate of 

 their relations to other Dinosaurs can be formed than has hitherto 

 been possible. They are evidently a highly specialized sub-order 

 of the great group which has the typical Ornithopoda as its most 

 characteristic members, and all doubtless had a common ancestry. 

 Another highly specialized branch of the same great order is seen 

 in the gigantic Ceratopsia, of the Cretaceous, which the writer has 

 recently investigated and made known. The skeleton of the latter 

 group presents many interesting points of resemblance to that of 

 the Stegosauria, which can hardly be the result of adaptation alone, 

 but the wide difference in the skull and in some other parts indicates 

 that their affinities are remote. A comparison of the present restor- 

 ation with that of Triceratops, recently published by the writer,^ 

 will make the contrast between the two forms clearly evident. 



All the typical members of the Stegosauria are from the Jurassic 

 formation, and the type specimen used in the present restoration 

 was found in Wyoming, in the Atlantosaurus beds of the Upper 

 Jurassic. Diracodon, a genus nearly allied to Stegosaurus, occurs 

 in the same horizon. Omosaurus of Owen, from the Jurassic of 

 England, is the nearest European ally now known, but whether it 

 possessed a crest of dermal plates like that of Stegosaurus is doubtful, 

 although caudal spines were evidently present. 



II. — The Scandinavian Glacier, and some Inferences 



DERIVED FROM IT. 

 By T. F. Jamieson, F.G.S. 



IT is now fifty years since Charpentier ^ told us that the heaps of 

 Northern boulders which stretch across the plains of Prussia 

 and Saxony mark the ancient limits of the great glacier of Scandi- 

 navia, and that the smaller debris met with farther south represents 

 the stuff carried on by the torrents that escaped from the margin of 

 the ice. All this he explained to his incredulous contemporaries, 

 and now after half a century of debate, in which every other con- 

 ceivable mode of accounting for the phenomena has been tried, it 

 seems to he agreed on all hands that he was right — right in every 

 particular — but, strange to say, it appears to be now generally for- 

 gotten that he was the man to whom we owe the first sketch of this 

 explanation. 



Agassiz,^ in 1846, alluding to the previous observations of Char- 

 pentier, candidly said, " I was unable to believe in his conclusions 

 when he first imparted them to me, and I made observations in order 



1 See Geol. Mag. Dec. III. Vol. VII. 1890, PI. I. pp. 1-5, and Vol. VIII. 

 1891, pp. 193-199, Pis. IV. and V., and pp. 241-250, PI. VII.; and Amer. Joum. 

 of Science, vol. xli. p. 339, April, 1891. 



■^ Essai sur les Glaciers, note to p. 319. 



3 BuU. Geol. Soc. France, 2 ser. iii. p. 420, 6 April, 1846. 



