BRITISH FOSSIL CRETACEOUS BIRDS. 497 



&c, 1869, I abandoned the generic name Pelagoniis (which had 

 been preoccupied by Lartet) for Enaliornis, and recognized a second 

 species. In that catalogue forty-seven fragments of bird-bones 

 arc enumerated and briefly described. In 1870, in " Eemarks on 

 Dimorphodon"*, I drew attention to the fact (afterwards confirmed 

 in American specimens by Prof. Marsh) that some dorsal vertebras 

 of Cretaceous birds have flat or slightly concave articular ends ; and 

 in other writings f I considered the affinities of the birds to be with Co- 

 lymbus J and the Penguins. Most of the Upper-Greensand bones were 

 found iu the neighbourhood of Coldham Common near Cambridge, or 

 at Granchester. When I was residing at Cambridge, and endeavoured 

 to add to the University collection every portion of the bird's skeleton 

 which came under my notice, I was never so fortunate as to secure 

 a perfect long bone ; and the only specimen which I have seen with 

 the shaft unbroken is a femur in the collection of Mr. Jesson, F.G.S. 

 Many of the fragments are worn ; but most are broken without being 

 much abraded. And it is quite possible that the specimens may 

 have been more perfect in the deposit than the state in which they 

 are collected would imply; but allowance, in judging of this, must 

 be made for the accidents of fossilization, and the carelessness and 

 ignorance of the phosphatite diggers, whose interest in these remains 

 is usually too small to ensure the preservation of inconspicuous bones 

 which are only met with at long intervals of time ; and thus por- 

 tions of one skeleton, or even of one bone, sometimes get distributed 

 to several collectors. In the remains of other animals I have seen 

 several cases in which the fragments of fractured shafts of bones 

 have lain in juxtaposition in the deposit, and oysters have grown on 

 the fractured surfaces — showing, I think, that though the nodules 

 may have been formed and mineralized in shallow water, they were 

 rolled, with such of the bones as are unassociated, into a somewhat 

 tranquil depth of sea before they were covered up by the Upper 

 Greensand sediment. 



There is no evidence of more than one bird-bone being found at a 

 time ; so that every fragment of bone may have belonged to a sepa- 

 rate individual bird. 



The Skull (PI. XXYI. figs. 1-4.) 



A suspicion often occurred to me that the hinder part of the cra- 

 nium (drawn in pi. 11. figs. 3-6 of my book on the Ornithosauria) 

 might perhaps be the skull of a bird. In describing it seven years 

 ago as Ornithosaurian I was influenced chiefly by probabilities and 

 considerations such as these : — The specimen closely resembles the 

 back part of the cranium in several Pterodactyles from Solenhofen ; 

 its Avian characters are in harmony with the characters of other 



* Annals Nat, Hist., Aug. 1870, p. 129. t Ibid. IS T ov. 1871, p. 305. 



$ May 2. 18G4, I communicated a note to the Cambridge Philosophical 

 Society " On the Fossil Birds of the Upper Greensand (Palceocolymbus Barretti 

 and Pelagornis SedgwicJci) ;" but nothing beyond the title of the paper was 

 printed. 



2m2 



