74 FOURTH FLOOR, SOUTH PAVILION 



all of the skeletons exhibited in these halls are of animals which lived 

 from 30,000 to 20,000,000 years ago. To prepare a specimen for 

 exhibition the matrix in which the bones are imbedded is carefully chipped 

 away and the missing parts restored in cement and plaster. The bones are 

 then assembled as in life. In the specimens on exhibition the restored 

 parts differ in color from the original parts of the skeleton and can readily 

 be distinguished. 



As a whole, the Museum collections of fossil vertebrates are believed to 

 be the finest in the world, if we take into consideration not merely numbers, 

 but also variety, quality and perfected methods of preparation and ex- 

 hibition. The collections illustrating the evolution of the horse are 

 probably equal to those of all other institutions combined. The collec- 

 tions of Permian reptiles, of Jurassic and Cretaceous dinosaurs, of turtles, 

 of North American Tertiary mammals, and of extinct mammals of South 

 America, are likewise of the first rank. There are more than seventy 

 complete skeletons on exhibition, several hundred skulls and nearly two 

 thousand jaws or other parts of various species. About ten times this 

 number are in storage, reserved for study and research, or not yet prepared 

 for exhibition. 



WEST CORRIDOR 



Fossil Fishlike Lizards 



Directly in front of the elevator is a wall case in which the most recently 

 acquired specimens are placed. The cases attached to the wall near the 

 stairway contain specimens of huge marine fishlike lizards, Avhich show the 

 tremendous pressure to which fossils are often subjected and the fragmentary 

 condition in which they are found. 



SOUTH PAVILION 



Mastodons and Mammoths 



The visitor should first enter the South Pavilion in which are shown the 

 skeletons of mammoths and mastodons, the prehistoric relatives of the 

 modern elephants, and of the curious and extraordinary extinct animals which 

 inhabited South America in prehistoric times, 30,000 to 100,000 years ago. 

 On the left is a series of modern skeletons illustrating the evolution of the 

 horse under the hand of man. Here are such extremes as the Shetland pony, 



