AVES. 



processes of bone beiug doubtless originally covered V)y 

 similar elevations of the horny beak, which would act like 

 teeth in dealinij^ with the slippery prey. This bird 



Table-case 

 13. 



was 



r-sr'v=^-■^---1^T^^■-'^p^^"^^^^^P^^ ^ 



Fig. 83. — Skull and lower jaw of Odontopteryx toliapica, with bouy denticles 

 on jaws, from the Loudon Clay of Sheppey ; two-thirds nat. size. 

 (Table-case 13.) 



probal ily related to the living gannets. Prophadhon resembles 

 a modern tropic bird, but has relatively larger hind legs. 

 Like the other fossils of the London Clay, these birds indicate 

 a subtropical climate in the south of England at the time 

 when they lived here. 



From the London Clay there is also part of a large 

 skull named Dasornis londiniensis by Owen, who thought 

 it might perhaps belong to a Eatite bird like the ostrich. 

 More satisfactory remains of a large running bird, Gastornis, 

 from the Lower Eocene of England, France, and Belgium, 

 sutrgest affinities with the geese rather than with the 

 ostriches. 



The earliest of all true and typical birds hitherto dis- 

 covered, are represented in Table-case 13 by a few bones of 

 Enaliornis from the Cambridge Greensand (Upper Cretaceous) 

 and by vertebra?, a pelvis, and limb-bones, with plaster casts 

 of other bones, of Ilesperornis from the Chalk of Kansas, 

 U.S.A. The vertebra with saddle-sliaped ends are especially 

 well preserved. These fossils seem to belong to swimming 

 birds like the existing divers (Cobjmhus) ; and the larger 

 bones from Kansas indicate a species If. regalis (Fig. 84), 

 which would measure from three to four feet in height. A 

 large drawing of a skeleton restored by the discoverer. 

 Professor 0. C. Mai'sli, is framed near the window. Hespev- 

 ornis has teeth in a groove in each jaw, though the extremity 

 of its upper jaw is toothless, and would prolSably be covered 

 with the usual horny beak. The bird must have been fliglit- 

 less, as indicated by its flattened breast-bone (sternum). A 



