GEOLOGICAL RELATIONS OF BIRDS. 237 
and its remains show a bony tail as long as the body, consisting 
of twenty separate vertebre with feathers implanted on either 
side (a pair to each vertebra), for its whole length, and radiating 
from its tip. It hada strengly curved “furcula” or merry- 
thought, and a keeled sternum. Its foot was completely like that 
of an ordinary bird, but in the pinion there were two distinct 
‘metacarpal bones and two curved claws. The wing was pro- 
vided with long “ remiges.” 
Remains of a Bird, the jaws of which bore true teeth, have 
been found in Sheppey*. It has been named Odontoptery« 
toliapus. 
Two very remarkable fossil Birds have been discovered in 
the Cretaceous rocks of North America. One of these, called 
Ichthyornis, differed from all existing Birds in having the centra 
of its vertebre concave both in front and behind. “It had also 
true teeth lodged in distinct sockets. Its wings were well 
developed ; its metacarpals anchylosed together, and its sternum 
keeled. The other form, called Hesper ornis, had true teeth 
lodged, not in distinct sockets, but in continuous grooves in the 
jaws. The centra of its vertebrae were saddle-shaped, as in 
ordinary birds, but its sternum had no keel. Its most extra- 
ordinary character, however, was its extremely defective wings, 
in which the skeleton of not only the pinion but of the fore-arm 
appears to have been absent, while the humerus itself, though 
long, was extremely slender. 
Some twenty other kinds of Cretaceous Birds have been 
described, most of them of wading, more or less aquatic kinds. 
Amongst these are Paleotringa and Telmatobius—allied to the 
Sandpipers and Rails. 
When we advance to the Tertiary epoch, a number of Bird- 
remains make their appearance. 
Amongst those found in the Eocene rocks in Europe are 
Alethornis and Protornis, the latter resembling a Lark, and 
Palegithalus, reminding us of a Nuthatch ; also Cryptornis and 
Haleyornis, which were like Kingfishers. The last-named fossil 
was found in the Isle of Sheppey, where also Zithornis was 
found, which seems to have been allied to the modern American 
Vultures of the genus Cathartes. A gigantic Wading-bird, called 
Gastornis, of the size of an Ostrich, has left its remains in France. 
An Eocene Woodpecker, Uintornis, has been found in America. 
* See Quart. Journ. Geol. Soe. xxix. p. 511. 
