378 Geological Society. 



The author concludes that he has established generally the curious fact, 

 that, in formations of all ages, from the carboniferous limestone to the 

 diluvium, the faeces of terrestrial and aquatic carnivorous animals have 

 been preserved ; and proposes to include them all under the generic name 

 of Coprolite. 



The examples he produces from the carboniferous limestone, the lias, 

 the Hastings sandstone, the chalk marl and chalk, the Maestricht rock, the 

 fresh-water deposits at Aix, and the diluvium, are taken respectively from 

 the several great periods into which geological formations are divided. 



May 15. and June 5. — Read. A paper *• On the Hydrographical Basin of 

 the Thames, with a view more especially to investigate the causes which 

 have operated in the formation of the valleys of that river, and its tribu- 

 tary streams; " by the Rev. W. D. Conybeare, F.G.S. F.R.S. &c. &c. 



The author has selected this river, not only as being the principal one 

 of the island, but further as exhibiting valleys exclusively the result of 

 denudation, and therefore better suited to illustrate that operation than 

 valleys of more complicated origin, in the formation of which the elevation 

 and dislocation of the strata have cooperated. 



He first offers some introductory remarks on the opposite theories of 

 the fluvialist and diluvialist, the former ascribing such denudations exclu- 

 sively to the operation of the streams actually existing, or rather to the 

 drainage of the "atmospherical waters, falling on the districts, which, it is 

 supposed, have become thus deeply furrowed by the gradual erosion of 

 these waters, continued through a long and indefinite series of ages; the 

 latter contending that such a cause is totally inadequate to the solution 

 of the phenomena, and maintaining that they afford evidence of having 

 been produced by violent diluvial currents. 



He proceeds to distinguish several different geological epochs, at which 

 it is probable that currents must have taken place calculated to excavate 

 and modify the existing surface. I. In the ocean, beneath which the 

 strata were originally deposited. H. During the retreat of that ocean. 

 III. At the periods of more violent disturbance, which are evidenced by 

 the occurrence of fragmentary rocks, the result of violent agitations in 

 the waters of the then existing ocean propagated from the shocks attend- 

 ant on the elevation and dislocation of the strata. — Four such periods 

 are enumerated as having left distinct traces in the EngHsh strata, 1. That 

 which has formed the pudding stone of the old red sandstone, ascribed to 

 the elevation of the transition rocks. 2. That which has formed the 

 conglomerates of the new red sandstone, ascribed to the elevation of the 

 carboniferous rocks. 5. That which has formed the gravel beds of the 

 plastic clay. 4. That which has produced the superficial gravel, spread 

 alike oyer the most recent and oldest rocks as a general covering, and 

 which is found to contain bones of extinct Mammalia : this (it is agreed) 

 may be identified as the product of one era, by the same evidence which 

 is employed to demonstrate the unity of any other geological formation. 

 Although diluvialists have usually directed their principal attention to the 

 effects of the currents of this latest epoch of general disturbance, they by 

 no means exclude the cooperation of any of the causes above enumerated. 

 In the body of his paper, the author considers the physical history of 

 the Thames as divisible into the following sections. I. The collection of 

 its head waters from the drainage of the Cotteswold uplands. II. The 

 passage which it has forced across the Oxford chain of hills. III. That 

 opened in like manner across the Chiltern Hills to the London basin at 

 Reading. IV. The re-entry of the river among those hills by the Henley 

 defile. V. Its course through the plains of London to the sea. 



I. The head waters of the Thames are collected from the drainage of 

 the Cotteswold uplands, over a tract about 50 miles in length, consti- 



