486 British Association for the Advancement of Science. 



those of a mere local character, such as volcanic eruptions. The 

 local phaenomena may indeed have been similar to those of the pre- 

 sent time, but the elevations of mountain chains are evidences of a 

 more general class of phaenomena, which have affected organic life, 

 constituting thereby the various zoological epochs which may be 

 traced in the earth's strata. It was in such periods of violence and 

 change that the beds of any one system were deposited, the animals 

 coexisting at the time being, according to the more or less suscep- 

 tible nature of their organization, more or less completely annihi* 

 lated ; and it was in the tranquillity which followed, that new beings 

 were formed, and lived to tenant in like manner the strata of another 

 system, which should result from another epoch of disturbance. 

 M. Agassiz produced, as an example of sudden destruction, a draw- 

 ing of fossil fishes crowded together in a very confused manner, 

 such as could only have arisen from an instantaneous catastrophe, 

 arresting them, as it were, in a moment. 



M. Agassiz then, at the request of Professor Sedgwick, explained 

 those characters, such as the position of the fins, the arrangement 

 and size of the scales, &c, by which the fishes of different geological 

 eras may be distinguished, referring especially to those of the old 

 and new red sandstones. 



1. On British Fossil Astacidae, their Zoological and Geological 

 Relations. 2. On British Belemnites. By John Phillips, 

 JF.R.S., G.S., Professor of Geology in King's College, London. 



(The leading results of these two communications, which form 

 part of a general investigation of British organic fossils, undertaken 

 at the request of the Association, will be given in the next volume 

 of Transactions.) 



Notice of a newly discovered Tertiary Deposit on the Coast of 

 Yorkshire. By John Phillips, JF.R.S., Sfc. 



Two hundred yards north of the harbour of Bridlington, near the 

 situation where Professor Sedgwick and the author and other ob- 

 servers had suspected and looked for tertiary beds, a wasting of the 

 low cliff had disclosed to a small extent layers of greensand and 

 clay, both, but especially the former, containing shells, &c. Diluvial 

 clay and pebbles cover and partially confuse this deposit. Of 55 

 species of fossils from these beds, which are in Mr. Bean's cabinet 

 at Scarborough, a very small number (four) belongs to the crag, a 

 very small number (five or six) to recent species, and the greater 

 proportion is extinct. On comparison of the facts known concern- 

 ing this deposit, the crag, the Touraine beds, and certain other fo- 

 reign tertiaries, Professor Phillips founded an argument concerning 

 the limits of error in the application of Mr. Lyell's test of the age 

 of tertiary formations by the numerical relations of the species of 

 fossils which they contain to recent forms. It appeared to Pro- 

 fessor Phillips that these limits were wide, and that a method of 

 such power and value must not be applied without great caution. 



