THE COLLECTION OF FOSSIL VERTEBRATES 9 



To give the visitor a clear idea of these extinct animals, the 



skeletons usually have been removed entirely from the rock in 



which they were found and have been mounted as „ x. •, 



1 -1 1 iM tio'w Fossil 



much as possible like skeletons of modern animals, skeletons 



To mount a petrified skeleton in this manner is a very are 



difficult matter, for such skeletons are rarely perfect, ^o^^^t^**- 

 and the bone is always very brittle and more or less shattered 

 and crushed out of shape. In the mounted skeleton the missing 

 parts have been restored in tinted plaster, modeled from other 

 individuals or from nearly related animals in which these parts 

 are known. The outlines of the restored parts of bones are 

 marked off with red lines, while entire bones modeled in plaster 

 are marked with a red cross, or with a red circle if supplied from 

 other individuals. All the skeletons are original specimens ex- 

 cept the Megatherium at the far end of the hall; and all are of 

 extinct animals except a few which are placed with the others for 

 comparison. With each fossil skeleton will be found, besides a 

 descriptive label, a small model and a water-color restoration of 

 the animal, showing its probable appearance during life and 

 indicating its supposed habitat. The transparencies in the win- 

 dows show the localities where the fossils are found, chiefly in the 

 Bad-lands of the western States. 



General Arrangement. 



The collections are arranged to illustrate the geological his- 

 tory and evolution of the difterent groups of Verte- General Ar- 

 brata, especially those of North America. They fill rangement 

 two large halls and a corridor. °^ ^°'^"- 



East Wing. Hall No. 406. Fossil Mammals. 



tions. 



