REPORT OF NATIONAL MUSEUM, 1920. 109 



Dr. W. H. Dull reports progress in indexing the Tertiary material 

 in liis charge. The largest additions to these collections have been 

 from the West Indies and are under the immediate supervision of 

 Dr. T. W. Vaughan. All have been given a preliminary examina- 

 tion, assorted into species, and tentatively identified. 



The skeleton of Brontotherium hatcheri Osborn has been added 

 to the exhibits of vertebrate fossils. This imposing addition to the 

 skeletons of large extinct mammals is the first and only mount of the 

 genus to be exhibited. As shown in the accompanying plate 2, 

 it forms an interesting illustration of the skeletal structure, and too 

 much praise can scarcely be a Horded Mr. Home for the mechanical 

 skill displayed in (he preparation. 



A long existing gap in our representation of the fauna of the 

 Niobrara Cretaceous is filled by the attractive and instructive exhibit 

 shown in plate 3. This skeleton of the large sea-living lizard, 

 Tylosaurus proriger Cope, is mounted in half relief as a panel on 

 the north wall of the main exhibition hall. It measures some 25 

 feet in length and, with the exception of the paddle bones of the 

 hind limb which pertain to a second individual, all the parts belong- 

 to this one specimen. The work of mounting was done by Mr. 

 Norman Boss with his accustomed skill. 



Other additions to the exhibition series in this division include a 

 skeleton of the diminutive camel, Stenomylus hitchcocki; skulls of 

 the musk-ox mounted on a panel in the alcove of Pleistocene speci- 

 mens; and four large Brontotherium skulls mounted for the Titano- 

 there exhibit. In addition Mr. Home prepared and mounted a finely 

 preserved bear skull and three skulls of the extinct peccary, Platy- 

 gonus cumberlandensis Gidley, male, female, and young, on a single 

 support, these last forming the nucleus around which it is proposed 

 to arrange a representative series of the Cumberland cave fauna. 



The refitting of the large cases in the east end of the vertebrate 

 hall has permitted an entire rearrangement of the materials, and 

 incidentally, the retirement of many fragmental specimens, thereby 

 greatly improving the appearance of the exhibit. 



A systematic arrangement of the study collections of mastodon 

 remains has been completed by Mr. Gidley, who is continuing his 

 studies on the Fort Union mammals and the Cumberland case col- 

 lections. Of the former, some 50 additional specimens have been 

 named or definitely determined so far as their generic and specific 

 characters are concerned. In this collection some 350 specimens 

 have already been catalogued. 



The preparators have as usual been employed not merely in the 

 preparation of material for exhibition, but in repairing broken speci- 

 mens, renovating cases, and cleaning up the more or less fragmentary 



