10 THE MISSOURIUM. 
8 inches. ach toe is possessed of four joints, and the thumb 
of three. The smallest and last of the joints of each toe shows 
plainly that it was armed with a nail; the nails of the right 
foot turned out towards the right, while those of the left were 
reversed and turned towards the left. The hind foot is much 
smaller than the fore foot; it has also four toes, but is desti- 
tute of the thumb. Its longest toe measures 1 foot 2 inches; 
its shortest, 93 inches. 
PECULIARITIES OF THE BONES. 
All the bones, without exception, are firm, and contain no 
marrow; I believe the marrow was superseded by an oily 
fluid, which circulated through the bones. 
All the vertebrze are remarkably narrow, and must have 
given the animal a superior degree of action in the back; this 
is more particularly observable in the vertebrze of the neck, 
which gives it the appearance of being very short. The two 
posterior vertebrze adjoining the os sacrum are united in one, 
which appears to have given the back more elasticity. . 
The ribs are remarkably slender and short in proportion to 
the size of the animal, and have had a great deal of cartilage 
attached to them: the six first are the strongest, and all have 
the singular peculiarity of standing half reversed in the body; 
that is, the edge of the rib bends in towards the intestines, and 
the opposite edge outwards, showing great lateral action. 
COMPARISON OF THE LEVIATHAN WITH THE MASTODON. 
The most striking difference between the Leviathan and the 
Mastodon, are, Ist, the Leviathan had no trunk, therefore 
could not be classed under the Probossa genus; 2nd, its toes 
were armed with claws or nails, and this circumstance pre- 
vents its being classed with the hoofed animals, to which class 
the Mastodon belongs; 3rd, the Leviathan has 24 dorsil ver- 
tebrze and 48 ribs; whereas the Mastodon has 19 dorsil ver- 
tebrze and 38 ribs; 4th, the scapula or shoulder blade is 
materially shorter in the Leviathan than in the Mastodon, also 
the ribs are much smaller; 5th, the dental system at the first 
view somewhat resembles that of the Mastodon, but upon a 
