August 16, 1895.] 



SCIENCE. 



179 



mens are the skeletons of Hyracotherium and 

 Phenacodus from the Wasatch and of Hyra- 

 ehyus from the Bridger. There are also 

 skeletons of Galecynus and Trispondylus, 

 and material for the restoration of several 

 other animals. Professor Cope has reserved 

 the right of describing the new material, 

 but the entire collection will be arranged 

 and placed on exhibition as rapidly as 

 possible, and will be permanently known 

 as the Cope Collection. A large new 

 storeroom on the upper floor of the new 

 wing of the Museum has been set apart 

 especially for it. All the specimens will 

 be numbered; the types designated under 

 the direction of Professor Cope, and all in- 

 formation regarding localities, dates, de- 

 scription, etc., will be entered on a special 

 card catalogue. The collection will thus 

 be made readily accessible to students. 



The Exhibition Hall on the third floor of 

 the new wing of the American Museum has 

 been designed and cased for the entire col- 

 lection of fossil mammals, and will be opened 

 for exhibition in November. The line of 

 large cases on either side of the centre of 

 the hall is designed for complete mounts of 

 Acerathermm, Metamynodon, Palceosyops and 

 Titanotherium and other animals now in 

 preparation. The smaller side cases will 

 contain morphological exhibits of the evo- 

 lution of members of the families ; also cases 

 arranged geologically to represent the faunte 

 of each horizon; and a series of upright A 

 cases designed for the exhibits of the evolu- 

 tion of the teeth, feet, skull and other 

 special parts of the skeleton. 



The expedition of 1895, the fourth which 

 has been sent out, entered the Uinta beds 

 early in the spring and explored the three 

 levels in which the Uinta deposits are di- 

 vided, as late as the water supplj^ admitted. 

 The party was then reinforced by a pho- 

 tographer, and, under the direction of Dr. 

 Wortman, moved north to the southern ex- 

 posure of the Washakie basin, east of the 



Green Kiver, and is now working in the 

 Uintatherium eornittum beds with consider- 

 able success. The work of these expedi- 

 tions is not confined to the collections of 

 fossil mammals, but to the careful survey 

 of the successive depositions in these various 

 basins. Every basin visited is explored 

 with the greatest care to determine the ver- 

 tical succession and horizontal distribution 

 of species. The main resiilt of this explo- 

 ration is to prove that each of the larger sub- 

 divisions of Leidy, Cope and Marsh is 

 capable of being divided into a number of 

 successive stratifications or beds, distin- 

 guished by characteristic species. The ap- 

 plication of this method was begun by the 

 Princeton expedition of 1880 in the surveys 

 of Professor McMaster, but unfortunately 

 was not followed up with sufficient care. 

 Several years ago Mr. J. B. Hatcher showed 

 that the lower portion of the White Elver 

 beds was capable of subdivision into three 

 clearly defined levels, and the American 

 Museum party of 1 893-94 proved that above 

 the Titanotherium beds five other specific 

 levels covild be determined, thus dividing 

 the White River beds into eight levels. In 

 1894 the Uinta beds were proved to be dis- 

 tinctly divided into three levels, the older 

 of which overlaps the somewhat older Wa- 

 shakie beds, and the uppermost overlaps 

 the beds of the more recent White River 

 beds, thus demonstrating that the Uinta is 

 the complete link between the Middle 

 Eocene and the Lower Miocene or Oligo- 

 cene. This summer the party is endeavor- 

 ing to determine the exact relations of the 

 Washakie depositions to the somewhat older 

 Bridger deposition west of the Green River. 

 Heney F. Osboen. 



THE GEOGRAPHICAL DISTBIBUTION OF THE 



IWLLUSCA. 



We hear a great deal of late concerning 



the habits, range of variation, and special 



characteristics of a great number of forms 



