342 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 90 



same genus, together with a life-size restoration made for the St. 

 Louis Exposition in 1904, constitutes a unique representation of this 

 curious armored dinosaur. 



Three skeletons of the mastodon race of proboscidians, a male and 

 a female of Mastodon cumericamis from the Pleistocene, and a skele- 

 ton of S teg mastodon arizonae from the Pliocene of Arizona are 

 adequate examples of this important group of animals. 



The outstanding addition to the collection, especially as it relates 

 to time and money expended, is the skeleton of Diplodocus longus 

 from the Dinosaur National Monument in Utah. The work of col- 

 lecting this specimen occupied the energies of 5 men for 4 months to 

 quarry out, transport, box, and ship the 26 tons of rock-enclosed 

 bones. From first to last, 2,545 Avorking days were spent on this 

 specimen, which, translated into Government time, means 1 man 

 working steadily for nearly 9 years. It constitutes the most ambitious 

 single piece of exhibition work ever attempted by this Division. 



All classes of vertebrates are now represented in the exhibition 

 series, which contains many well-preserved skeletons. Little attempt 

 has been made to bring about a systematic arrangement of these 

 materials, more stress being given to displaying the larger specimens, 

 so as to make them as well as the exhibition halls appear to the best 

 advantage. 



With the acquisition of better-preserved specimens, the practice 

 has been followed of retiring inferior materials from time to time. 

 This has added greatly to the attractiveness of the exhibition as a 

 whole, as well as increasing its educational value to the public. 



To some extent the exhibition has been embellished by the addition 

 of large canvases depicting the life appearance of various animals 

 in their natural habitat. The more important of these are : A resto- 

 ration (8 by 15 feet) of Triceratops by Charles R. Knight, W. K. 

 Stone, and Joseph Gleeson; a restoration of Camairasaunis by 

 E. Bruce Horsfall; and a restoration of Dimetrodon and other Per- 

 mian reptiles by Garnet W. Jex. A diorama returned from the 

 Dallas Exposition depicts some of the animals of the Jurassic period 

 in their natural environment. Other illustrative materials consisting 

 of model restorations of various animals, done by Knight, Lull, 

 Gidley, and Gilmore, serve as an aid to visitors in visualizing the 

 probable appearance in life of these long extinct animals. 



