TRANSACTIONS OP THE SECTIONS. 93 



Considerations on Geological Evidence and Inferences. By R. C. 

 Austen, F.G.S. 



The object of this communication was to examine the soundness and 

 applicability of certain geological inferences, regarding the ancient 

 land and sea, which have been freely adopted, sometimes in a general 

 sense, upon local and limited data, insufficiently compared (the author 

 thinks) with the laws of existing nature. The subjects discussed were 

 the geographical areas over which particular mineral characters extend, 

 and the degree in which the conformity of such characters is to be 

 esteemed evidence of contemporaneous deposition; the succession of 

 organic life in the ancient land and sea, and the contemporaneity of 

 identical species in unconnected deposits and distant quarters of the 

 globe ; and ancient climate. The investigation does not admit of con- 

 densation, but the following are among the author's conclusions : — 

 1. — The identification of strata by zoological characters can never 

 be done, except over very limited areas ; a few degrees of lati- 

 tude must always have brought about a perfect change. 

 2. — Along the same line longitudinally analogy does not allow us to 

 expect a much wider range of the same animal or vegetable 

 forms. 

 3. — Organic remains offer no proof whatever that the distant depo- 

 sits are contemporaneous, but rather are proofs to the contrary ; 

 viz. that contemporaneous deposits, in situations removed from 

 each other, can never have had zoological characters in common. 

 4. — Mineralogical character is only evidence as to a certain condition 

 of water, under which the deposit was formed. Nor is inclined 

 stratification a necessary consequence of disturbance, as some 

 of the beds of recent stratified sandstone in Devon and Corn- 

 wall have been deposited at high angles. 



On Lunar Volcanos. By T. W. Webb. 



The author, after showing the inadequacy of some of the grounds 

 upon which the activity of lunar volcanos is often maintained, states 

 the result of particular observations which appear to him to support 

 the conclusion. 



" It is obvious," he observes, "that either the formation of new craters, 

 or the enlargement of those previously existing, would afibrd convincing 

 proof of the continuance of explosive or eruptive action : and having 

 examined several portions of the moon with an excellent achromatic 

 telescope of five-feet by TuUy, with the express view of detecting any 

 appearances of the kind, I think I am enabled to assert that both the 

 one and the other of these changes have taken place since the observa- 

 tions of Schroter at the close of the last century." 



The general result is, that craters apparently of recent origin, and 

 not to be found in Schroter's plates, are now equally conspicuous with 



