294- Geological Society. 



On the subject of tertiary deposits, I have finally to notice a com- 

 munication by Mr. Pratt, who found, during last summer, in the 

 lower freshwater marls of Binstead in the Isle of Wight, many com- 

 minuted or rolled fragments of the bones and teeth of several species 

 of Mammalia, mingled with pulverized shells, and with the bones of 

 two or three species of freshwater turtles, resembling those described 

 by M. Cuvier from the Paris basin. Among the more perfect speci- 

 mens of these fossils, the author found a tooth of the Anoplotherium 

 commune, and the teeth of two species of Paloeotheria ; thus confirm- 

 ing a previous discovery made known by Mr. Allen, and perfecting 

 the zoological analogy between the newer lacustrine formations of 

 England and central France. 



The bones of the Binstead marls do not however belong exclu- 

 sively to the order of Pachydermata ; for the author also found the 

 jaws of a ruminating animal closely allied to the genus Moschus, but 

 at the same time differing in some essential characters from every 

 species hitherto described; and he gives us reason for sanguine hope, 

 that large additions may be hereafter made to his very important list 

 of new fossil quadrupeds. All the magnificent generalizations of 

 Cuvier, as far as they are borne out by the zoological phenomena of 

 the Paris basin, apply therefore literally to the more recent physical 

 revolutions of our own country. 



Among the papers published in the early volumes of our Trans- 

 actions, none excited a greater or more deserved interest than 

 those of Mr. Webster. But first generalizations are almost always 

 pushed too far. After being bewildered with the observation of un- 

 connected facts, the first glimmering of general truth is so delightful, 

 that it often leads us beyond the bounds of fair induction. We are then 

 compelled to retrace our steps, and cast about for new phenomena j 

 and it is only after a succession of trials and adjustments, that the 

 facts we had at first partially misinterpreted are seen at their pro- 

 per level, and with their true bearing upon each other. The broad 

 conclusions of Mr. Webster, in his comparison of the basins of Paris 

 and the Isle of Wight, are however too firmly established to be ever 

 shaken j and it is only in his estimate of the subordinate groups that 

 his early essays require either revision or correction : and surely it 

 is no reproach to him that he did not foresee the subsequent disco- 

 veries of MM. Cuvier and Brongniart. 



The argile plastique of Paris is now regarded as a mere local lacus- 

 trine deposit. The plastic clay of this country is, on the contrary, an 

 arenaceous formation of enormous thickness, not merely coextensive 

 with, but often stretching far beyond the limits of, our tertiary basins ; 

 and containing, here and there, subordinate argillaceous beds, and 

 many marine shells of the same species with the characteristic fossils 

 of the London clay. 



The deposits of the Isle of Wight above the London clay are sub- 

 divided (in all our published works) into three principal groups, the 

 upper and the lower composed of calcareous lacustrine marls in diffe- 

 rent states of induration the middle one of argillaceous marls sup- 

 posed to be exclusively of marine origin. But it has been long known 

 to many of the gentlemen I am now addressing, and to no one better 



than 



