Mr. Lyell's Address. 393 



on which they have been deranged. I collected fossil plants on the 

 Col de Balme, but I have not examined the precise localities further 

 to the west appealed to by M. de Beaumont. I am far, therefore, 

 from denying his facts or inferences, hoping at some future period 

 more carefully to inquire into the evidence on the spot. No one, I 

 am aware, is more desirous that others should visit the southern 

 Alps and verify or criticise his facts than M. de Beaumont. Mean- 

 while I am reminded of an expression of our mutual friend M. von 

 Buch. When I related to him some geological phaenomena which 

 surprised him ; ** I believe it," he said, " because you have seen 

 it, but had I only seen it myself, I should not have believed it." 



But to conclude, and to recall your attention to the structure of 

 Devonshire, you will perceive that Mr. Murchison and. Professor 

 Sedgwick have endeavoured, and I think successfully, to work a 

 great reform in the classification of the ancient rocks of that 

 country, by applying to them the arrangement which they had pre- 

 viously made for the deposits termed by them Cambrian and Lower 

 Silurian in Wales and the adjoining parts of England. According 

 to their survey and sections the coal plants of Bideford, so far 

 from constituting any anomaly, so far from affording any objection 

 to the doctrine that particular species of fossil plants are' good tests 

 of the relative age of rocks, do in reality from the place which they 

 occupy, confirm that doctrine ; for the culmiferous rocks distinctly 

 overlie the so-called grauwacke, and are not referable to any of the 

 well-defined and normal types, which compose the old Red Sand- 

 stone and Silurian System. 



I shall now pass on to the consideration of other memoirs on En- 

 glish Geology. The limestone which the Germans call muschelkalk, 

 and the numerous fossils which are peculiar to it, have not yet been 

 detected in England in any part of that great series of beds which 

 intervene between the lias and the coal. In those parts of Germany 

 where it occurs, it divides the beds of red marl and sandstone which 

 occupy that great interval into two divisions, the upper of which 

 is called keuper, and the lower hunter sandstein. In the absence 

 of the muschelkalk in this country, it has been impossible for us 

 to separate our new red sandstone into two well-defined masses ; 

 but Dr. Buckland considers that certain portions of the upper beds 

 in Warwickshire and elsewhere may be identified with the keuper 

 by their mineral character, and near Warwick by the remains of a 

 Saurian, which he believes to be of the genus Phytosaurus, a genus 

 characteristic of the keuper of Wirtemberg. 



An examination in the South-east of England of the strata usually 

 termed plastic clay, has led Mr. John Morris to offer several new, 

 and as they appear to me, judicious suggestions in regard to the 

 classification of these beds. It is well known that wherever the 

 tertiary strata are seen in immediate contact with the chalk, they 

 consist of alternations of sand, clay, and pebbles, and in some 

 few places a calcareous rock, — all these varying greatly in their 

 thickness, and in their order of succession in different places. 

 Mr. Morris divides those of Woolwich into two parts, and states 



Third Series. Vol. 10. No. 62. Ma^ 1837. 3 E 



