272 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1921. 



in keeping with the national character of the institution. The six 

 principal sources of accessions are (1) purchase, of which there are 

 but few, (2) transfer from other Government departments, (3) oc- 

 casional collecting expeditions, (4) exchange of duplicate materials, 

 (5) gift, (6) deposit. Of these numbers two and three are by all 

 means of greatest importance numerically. 



The exhibition collection, begun in a modest way more than a 

 quarter of a century ago by the installation of a mounted specimen 

 of an Irish Elk and casts of a Glyptodon and giant sloth, now forms 

 a very important part of the department of geology. It may be said 

 to have had the beginning of its present development with the 

 mounting of the duck-billed dinosaur (Trachod&n awnectetos) , in 

 1902, the second dinosaur skeleton to be mounted in the United 

 States, first honors having gone to Yale University, where a com- 

 panion specimen was placed on exhibition the year previous. 



Since 1902, and especially since occupying improved quarters and 

 more ample show space in the new Natural History Building (pi. 5), 

 other skeletons have been added to the exhibition series from time to 

 time, until there is now a total of 40 articulated representatives of the 

 three great classes of animal-life — birds, reptiles, and mammals. 

 These vary in size from a small horned rodent (Epigaulus hatcheri, 

 pi. 7, fig. 2) 12 inches in length, to the whalelike Basilosaurus that 

 measures 55 feet over all. Numerically this number may appear small, 

 but when the rarity of mountable specimens is taken into considera- 

 tion and especially the great length of time required to prepare 

 them, it makes a creditable showing for the small force engaged in 

 the work. 



The larger skeletons are arranged in the center of the main hall. 

 In placing these more attention has been given to display and to 

 their conformity to the space occupied than to any systematic 

 arrangement, although the hall is roughly divided between repre- 

 sentatives of the mammals and reptiles, the former predominating 

 in the western half, the latter in the eastern portion. Of the larger 

 specimens, those deserving especial mention are the Basilosaurus 

 cetoides, a long and slender marine mammal, which occupies a promi- 

 nent place in the center of the hall opposite the entrance from the 

 rotunda. The skeleton remains of this animal were collected by Mr 

 Charles Schuchert in 1894 and 1896 from the vicinity of Cocoa, Ala. 

 This constitutes the first approximately correctly assembled indi- 

 vidual of this peculiar animal ever to be mounted. It may be of in- 

 terest to recall the grotesque restoration by Koch which he recon- 

 structed from Basilosaurus bones some years ago and which was 

 widely exhibited. This restoration, which Koch called Bydrarckos, 

 was made up of the bones of many individuals, and gave a very ex- 

 aggerated idea of its length and proportions. 



