THE EOCENE PERIOD. 297 
west of England, there occur fossil remains of all the three 
living types of Crocodilians—namely, the Gavials, the true 
Crocodiles, and the Alligators (fig. 226)—though at the 
Fig. 226.—Upper jaw of Alligator. Eocene Tertiary, Isle of Wight. 
present day these forms are all geographically restricted in 
their range, and are never associated together. 
Almost all the existing orders of Azrds, if not all, are 
represented in the Eocene deposits by remains often very 
closely allied to existing types. Thus, amongst the Swimming 
Birds ((Vatatores) we find examples of forms allied to the 
living Pelicans and Mergansers; amongst the Waders (Gra/- 
Jatores) we have birds resembling the Ibis (the Mumenzius 
gypsorum of the Paris basin); amongst the Running Birds 
(Cursores) we meet with the great Gastornis Parisiensis, which 
equalled the African Ostrich in height, and the still more 
gigantic Dasornis Londinensts; remains of a Partridge rep- 
resent the Scratching Birds (Rasores) ; the American Eocene 
has yielded the bones of one of the Climbing Birds (.Scan- 
sores), apparently referable to the Woodpeckers ; the Profornis 
Glarisiensis of the Eocene Schists of Glaris is the oldest 
known example of the Perching Birds (/msessores); and the 
Birds of Prey (Raptores) are represented by Vultures, Owls, 
and Hawks. The toothed Birds of the Upper Cretaceous 
are no longer known to exist; but Professor Owen has 
recently described from the London Clay the skull of a very 
remarkable Bird, in which there is, at any rate, an approxi- 
mation to the structure of /chthyornis and Fesperornis. The 
bird in question has been named the Odontopteryx toliapicus, 
its generic title being derived from the very remarkable char- 
acters of its jaws. In this singular form (fig. 227) the margins 
