10 ANNUAL REPORT SlVflTHSONIAN INSTITUTION, 1908. 



opportunity for the observation of the unique phenomena at the 

 crater, and Doctor Merrill was authorized to proceed again to Ari- 

 zona to be present during this second, and probably final, series of 

 drillings. The greatest depth reached during his stay at the crater 

 was 842 feet, and the results of the examination of the ejectamenta 

 thus secured confirmed the former conclusion. Several boxes of 

 specimens bearing on the subject were forwarded to the Institution, 

 where they will be held for future reference and study. 



ALASKAN EXPEDITION. 



In my last report mention was made of an expedition to be made 

 to the Yukon country in Alaska for the collection of the remains of 

 large extinct vertebrates, particularly mammals. A Smithsonian 

 expedition had been made to this region in the summer of 1904 by 

 Mr. Maddren, the results of which were jDublished by the Institution 

 in 1905. The present expedition of 1907 was in charge of Mr. C. W. 

 Gilmore of the National Museum. The results of the explorations 

 have been published in the Smithsonian Miscellaneous Collections. 



Mr. Gilmore was not successful in finding what was most desired, 

 a fairly complete skeleton of a mammoth, but the expedition was by 

 no means barren of results. He found that scattered remains of 

 Pleistocene animals occur throughout the unglaciated region of 

 Alaska and adjacent Canadian territory in the black muck accumu- 

 lated in gulches and the valleys of the smaller streams, in the fine 

 elevated clays of the Yukon silts, and Kowak clays, and in the 

 more recent fluvial and alluvial deposits. Some of the specimens are 

 so well preserved that they could not have traveled far from the 

 original place of interment, while many bones are broken, abraded, 

 and waterworn. Mr. Gilmore gives a list of the various genera and 

 species of extinct vertebrates thus far reported from Alaska, followed 

 by a brief review with a number of illustrations. He believes that 

 Avhen more perfect material is available it will be found, probably 

 in all instances, to be quite distinct from the living forms. The 

 skull of an Omhos Avas found sufficiently complete to warrant its 

 separation from the living form 0. moschatus^ to which nearly all 

 musk-ox material from this region had previously been referred. 



GEOLOGY OF THE ALPS. 



The investigation by Mr. Bailey Willis of the current theories of 

 Alpine structure, under the grant approved in 1907, was successful 

 in olloring opportunities for consultation with leading European 

 geologists, among whom were Rothpletz, Suess, Lugeon, Margerie, 

 and Saccord. In cooperation with several distinguished students of 

 the great problems of the Alps, Mr. Willis made detailed studies of 



