228 Geological Society. 



Perthshire, scales, teeth, and bones of fishes ; and, by comparing these 

 remains with a magnificent specimen of a fish from Clasbennie, in Mr. 

 Murchison's possession, Mr. Malcolmson has ascertained this suppo- 

 sition to be correct. A doubt, therefore, which formerly existed re- 

 specting the age of the conglomerate, is now removed. 



The paper concluded with an account of eleven ancient beaches on 

 the coast, rising above each other, and from one of which, 15 feet 

 above high- water mark, and cut through in draining Loch Spynie, 

 Mr. Malcolmson procured twelve species of existing marine tes- 

 tacea. 



A paper, " On the Origin of the Limestones of Devonshire," by 

 Robert Alfred Cloyne Austen, Esq., F.G.S., was afterwards read. 



The object of the paper is not to account for the origin of calca- 

 reous matter, or the means by which marine animals derive it from 

 the surrounding medium, but to show how far the limestones of 

 South Devonshire may have been produced by polypi. 



These limestones are stated by the author to occur, in nearly every 

 instance, in the immediate vicinity of volcanic disturbances, and to 

 be partly included in the slates and sandstones, and partly to rest 

 upon them. To the former belong the broad band extending from 

 Staple Hill to Dean Prior, the minor bands in the neighbourhood of 

 Hempstone and Totness, and all those which occur beyond the Dart ; 

 also the limestones of Newton and Torbay. They are said to be 

 less pure and more slaty than the overlying limestones, and to be 

 frequently separated by seams of shale. Transverse sections of these 

 bands show, that the strata in some cases become thinner as they 

 descend, and that the partings of shale increase, as near Staverton 

 in the vaUey of the Dart, and at Staple Hill ; but that in other in- 

 stances, as between Newton and Totness, the strata instead of fining 

 off end abruptly upon the slate, and are covered in the direction of 

 the dip by similar slates. The strata are always inclined, but they 

 invariably form a table-land at the surface. This inclined position 

 the author conceives is not due to dislocation, but to the beds having 

 been deposited at the angle which they now present ; and he illu- 

 strated his opinion, by a section between three and four miles in length, 

 through the parishes of Pegwell, Denbury, and Abbots Kerswell, a 

 remarkably level country. The bands of limestone dip 40°, but are 

 nowhere more than 150 feet thick, and they all contain the same de- 

 scription of organic remains. If the bands were deposited horizon- 

 tally, and the most recent nearly at a level with the surface of the 

 ancient ocean, then the lower beds, the author says, would have been 

 placed at a depth of nearly three miles, although the organic remains 

 prove that all the beds were formed under precisely similar condi- 

 tions. 



In the structure of the Devonshire limestones, however, Mr. Austen 

 considers that he has discovered evidences of an origin similar to that 

 of modem coral reefs, and which will explain their inclined position. 

 At Ogwell Park the limestone forms a horizontal capping to the in- 

 clined strata; and at Bradley rests conformably against a ridge of slate 

 the basset edge of each bed rising to the level of the crest of the ridge. 



