﻿Ixvi PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



them adhere to their sockets, render it more than ever inexplicable 

 why hundreds of similar detached teeth should have been previously 

 collected by naturalists without their having fallen in with a single 

 fragment of a jaw-bone. 



If it appear singular that the first terrestrial quadrupeds of older 

 date than the eocene strata should have been met with in a marine 

 limestone at the bottom of the oolite, rather than in the freshwater 

 strata of the Wealden, where the remains of herbivorous reptiles 

 abound, I may observe that it is not more strange than that no land 

 shells should yet have been discovered in the Wealden, or that no 

 pulmoniferous mollusca should have been met with, until the recent 

 researches of Messrs. Dunker and E. Forbes had made them known 

 in Hanover and Dorsetshire. 



The last remaining point respecting the development of the more 

 highly organized vertebrata in the older rocks, on which I propose 

 to oifer some comments, relates to the absence of Cetacea and of all 

 marine mammalia in formations more ancient than the eocene. I 

 agree with Professor Owen, that no argument founded on negative 

 evidence, in favour of the imperfect development of the class of ver- 

 tebrata in the earlier periods, is entitled to so much weight as the 

 dearth of fossil cetaceans in these primary and secondary strata of 

 marine origin. Professor Sedgwick indeed states in his recent work*, 

 that he possesses in the Woodwardian Museum a mass of anchylosed 

 cervical vertebrae of a whale, which he found near Ely, and which 

 he has no doubt came from the Kimmeridge clay, because it is in the 

 same state as other fossil bones procured from that formation. Prof. 

 Owen, who has examined it, says that it exhibits well-marked specific 

 characters, distinguishing it from all other known recent or fossil 

 cetacea. If there were not drift-clay as well as Kimmeridge clay in 

 the low region where these vertebrae were picked up, it would be a 

 decisive indication of a marine mammal of the period of the upper 

 oolite. It was probably derived from that formation ; but the deter- 

 mination of its true site is not so satisfactory as could be wished, 

 where the fossil bears on a theoretical point of such extreme import- 

 ance in palaeontology. 



According to the i Index Palaeontologicus ' of Bronn, Morren has 

 described a Tubicinella from the chalk of Belgium ; and Mr. Darwin, 

 * Preface to 5th Ed. of Studies of Cambridge. 



