THE HALL OF FOSSIL VERTEBRATES 
pigs and peccaries, camels, deer, sheep and cattle. Four skele- 
tons and numerous incomplete specimens represent these last. 
The south side of the hall is devoted chiefly to the Perisso- 
dactyls or Odd-toed Hoofed Mammals. First come the Titan- 
otheres, an extinct group, once abundant in North America, 
whose evolution is here illustrated by two skeletons and a series 
of skulls; then the Rhinoceroses, also abundant in North Amer- 
ica in former geological epochs, represented here by six complete 
skeletons and a large series of skulls; after these the Horses, 
whose evolution is illustrated by two skeletons and many skulls 
and feet. At the eastern end of the hall is a cast of the skeleton 
of the Megathertum, or great Ground Sloth, the largest of a sin- 
gular group of mammals which inhabited South America until 
the advent of Man in that part of the world. 
Fossit REPTILES. 
The Dinosaurs, or giant reptiles, have been placed tempora- 
rily in two wall cases at the east end of the hall, and in the two 
high cases to the north of the centre aisle. Small models of res- 
torations of three kinds of dinosaur will be found in an ‘‘A’’-case 
near the east end of the hall, near the centre aisle. 
These were the great terrestrial vertebrates of their day, the 
Age of Reptiles, and they assumed an extraordinary variety of 
forms, but all had long hind limbs and a long and massive tail. 
Some of the Sauropods (e. g., Brontosaurus, Diplodocus, Moro- 
saurus), four-footed, long-necked, herbivorous, probably amphibi- 
ous, were beyond comparison the largest animals that ever trod 
the earth and can be compared in sizeonly with the modern whales. 
Incomplete skeletons of these monstrous beasts are shown in 
this hall. Others, the Megalosaurs, were two-footed, carnivorous, 
preying on the clumsy giants (Sauropods) with which their 
remains are found associated in the rock. Others again, the 
. Stegosaurs and Ceratopsians, or armored dinosaurs, were short- 
necked quadrupeds, massively proportioned, with back and tail 
covered by heavy bony plates and spines. Another group, the 
Ornithopods or Iguanodonts, long-limbed bipeds— or rather 
tripeds, for the long and massive tail formed a third support,— 
16 
