24 GEOLOGICAL SURVEY 
Pachydermata—(Continued.) 9. Order, Ruminantia. 
Elasmotherium. Urus—Auroch. 
Paleotherium. Bos— Ox. 
Anoplotherium. Capra— Goat. 
Xiphodon. Cervus— Roe. 
Dichobunes. Dama— Deer. 
Cheeropotamus. Megaceros. 
Anthracotherium. Sivatherium. 
Adapis. 10. Order, Cetacea. 
Hyracotherium. Manatus. 
Sus--Hog. Baleena. 
8. Order, Solidungula. Monodon. 
Equus—Horse. Delphinus. 
Zeuglodon. 
Birds.—But few remains of birds are found in any country. The foot-prints in the sandstone of 
Connecticut, however, afford positive evidence of the existence of this class of vertebrata, as far 
back as the secondary period. Many of these foot prints are of extraordinary size, being fifteen 
inches in length; and the length of the strides of the bird, as indicated by the impressions on the 
sandstone, was from four to six feet. The vast proportions of a bird capable of such strides as 
these, for some time induced doubts as to the true nature of these “ornithicnites.” ‘The persevering 
labors of Prof. Hitchcock and Dr. Deane, in this novel field of enquiry, removed all scepticism, at 
least on this side of the Atlantic. And abroad the discovery of the osseous remains of a gigantic 
bird, fully proportionate to the largest foot-prints on the Connecticut sandstane, removed all doubt. 
In New Zealand the bones of birds were found imbedded in mud, one of which, the largest bone 
of the leg, measured twenty-eight inches in length. These relics were described by Professor 
Owen, under the name of Dinornis. 
The cranium of birds presents a remarkable peculiarity in the early coalescence of its separate 
bones, so as to appear as if composed of one. The lower jaw articulates with it by means of the 
os quadratum, as in reptiles. 
In general the bones are hollow, thin and smooth ; those of the trunk are hard and elastic, and of 
the extremities brittle. 
Taken in connection with the foot prints left on the solid rocks, the peculiarities of the form of 
the feet become a matter of some interest. 
When there are four toes, three of them are directed forward and one backward, which may be 
called the thumb: in the latter there are two joints, in the first on the inside there are three, in the 
next four, and the outer toe has five joints. When the bird has but three toes, two are directed 
forward. The hind toe, in this case, has three joints, and the others four and five respectively. 
We have here, then, a simple means of inferring, with confidence, the existence of birds from 
their tracks, in the absence of other evidence ; as no other animals have feet presenting the same 
organization. 
Reptiles.—The following are the types to which living reptiles are referred. 
