Jan., 1907. Annual Report of the Director. 31 



appearance. A relief map illustrating the oil-fields of the United 

 States has been prepared and hting in Hall 71, devoted to petroleum 

 and its products. This map is uniform in size and treatment with 

 those already on exhibition, illustrating the distribution of zinc, 

 copper, and iron ores. In Halls 76 and 77, devoted to physiographic 

 geology, fifteen of the large relief maps have been covered with glass. 

 This insures protection from further injury by dust and enhances 

 the appearance of the display. The collections in Hall 78 have been 

 remounted and relabeled throughout. A number of additional 

 shelves have been provided for the cases, in order to accommodate 

 the large increase in the collections due to material received chiefly 

 from the Louisiana Purchase Exposition. These include large 

 additions to the series of abrasives, salt, barite, phosphates and micas. 

 The mounting is in the shape of individual blocks and stands calculated 

 to exhibit each specimen to the best advantage. The four large 

 floor cases containing the collection of gems in Higinbotham Hall have 

 been thoroughly renovated. The case linings having become much dis- 

 colored through age and the entrance of dust, the cases were therefore 

 completely relined with white silk crepe. Pads of the same material 

 bound with white silk cord were prepared, and upon these the individ- 

 ual specimens have been mounted. New labels printed on white 

 cardboard have also been provided. Thus, a background of uniform 

 color is obtained, against which the gems form the only coloring, and 

 the effect is very satisfactory. Case labels were also provided for 

 the cases in this hall throughout. For the large Triceratops skull 

 collected by the Paleon to logical Expedition in Montana in 1904, a 

 special case 5x7x7 feet was constructed and installed in Hall 36. The 

 large Mosasaurus slab, 3x12 feet, obtained the same year, was installed 

 in one of the wall cases in Hall 59. Other specimens of fossil verte- 

 brates installed include large skulls of Elotherium and Accra the rium, a 

 skeleton of Dinictis, and several smaller skulls. The wall cases in 

 Hall 66, containing volcanic products, rock textures, etc., have been 

 thoroughly cleaned and the specimens reinstalled. Such work of 

 cleaning and reinstallation, made necessary by the temporary cases 

 employed, will not be required when permanent cases are provided. 

 Three individual fulgurites have been assembled and mounted. In 

 the paleontological laboratory the following specimens have been 

 worked out and mounted: Complete skeleton of Mosasaurus twelve 

 feet long; complete skeleton of Dinictis felina; complete head of 

 Elotherium ingens; complete head of Hyracodon nebrascensis ; 

 two skulls of Accra therium; two skulls of Mesohippus bairdii; one 



