ANNIVEESARY ADDEESS OF THE PKESIDENT. XXXUl 



existence of a patch of Lias in Banffshire. Another unexpected and 

 equally interesting fact has been ascertained by Mr. Binney — the 

 occurrence of Lias on the Trias of the plain of Carlisle, like that far- 

 separated tract which Murchison made known on the red marls of 

 the Cheshire plain. This discovery is the more important, as leaving 

 no room for doubt as to the true age of the red marls and sandstones 

 of the plain of Carlisle. They are certainly Triassic, and, hke those 

 of the Yale of Clwyd, lie at the foot of a chain of hills thrown up 

 before their date ; among the dislocated beds we find the Permian 

 calcareous conglomerates. Do they cover coal ? 



The important share in the accumulation of the materials of the 

 strata which is due to the action of ancient currents and surfaces of 

 fresh water has become fully recognized. In a table some time since 

 drawn up by Prof. Ramsay*, the deposits of fresh water, pure or 

 mixed with estuarine or littoral deposits, have been ranged in order, 

 and we see that from the Middle Palaeozoic era at least, traces of this 

 action are apparent in every period. There seems likely to be always 

 a difficulty in giving exactness to conclusions regarding the date of 

 these deposits, where they do not alternate with the marine strata 

 which really mark the scale of geological time. This kind of doubt 

 remains to some extent in regard to the freshwater and estuarine 

 beds of Shotoverf; for, though they rest upon Portland beds, and 

 are covered by Cretaceous strata, we have rarely found critical marks 

 for the exact age of the latter. The observation of W. Smith, made 

 nearly sixty years since, of Gault fossils overlying the sands at Step- 

 pingley Park, is of value in narrowing the limits within which to 

 define the age of the sands of "Wobum and Shotover. 



I must not conclude this notice of maps without calling your 

 attention to the very instructive example fiu-nished by Mr. Mylne of 

 a local map, on a scale of magnitude adequate to practical purposes. 

 The Map of the Geology of London will probably be copied on many 

 occasions hereafter in other cities, where questions of importance 

 touching the health and internal economy of the crowded masses of 

 men shall have acquired the attention they deserve. I should also 

 much wish to see produced some maps of estates coloured geologi- 

 cally, on the model, now a quarter of a century old, of the admirable 

 map of Hackness by Wilham Smith. 



I take this opportunity of expressing my extreme gratification at 

 the completion of that labour of love, the Classified Index to our 

 publications, for which we are indebted to Mr. Ormerod. This work 

 is perhaps the more important, as the Journal of the Society will in 

 future be issued to all the resident members, and will therefore have 

 a wider circidation. 



Constitution of Rochs, 



Among the subjects which have acquired prominence during the 

 past year, I wish to distinguish on this occasion, as specially de- 

 serving long and careful study, the chemical composition, molecular 



* See Edinb. New Phil. Journ., new series, vol. iii. p. 315. 

 t Phillips in Quart. Joura. Greol. See, 1858. 



