80 REPORT OE NATIONAL MUSEUM, 1924 



States Bureau of Soils engaged on the Columbia Basin irrigation 

 investigations, and, through the efforts of Dr. Kirk Bryan, was re- 

 covered and forwarded to the Museum. 



As a part of a collection received in exchange from Colorado Col- 

 lege, Colorado Springs, were the types of the plesiosaur Trinacro- 

 merum oentonianum Cragin, and of the turtle Testudo equicomes 

 Hay; as a donation from Dr. David Starr Jordan, the types of a 

 fossil sculpin from Nevada. All are important additions to the 

 steadily growing series of type material. 



Interesting materials from South America, presented by Brother 

 Ariste Joseph, Instituto de la Salle, Bogota, include good teeth of a 

 species of mastodon, part of the carapace of a fossil armadillo, jaws 

 of ground sloths, and several good specimens of other mammals be- 

 longing to a peculiar group known as the Notungulata. 



A single dorsal vertebra of an extinct lizard, of interest as be- 

 longing to the most ancient lizard yet found in North America and 

 from the fact that it will become the type of a new species, was re- 

 ceived as a gift from L. S. Russell, of the University of Alberta, 

 Canada. 



Important cetacean remains, of which partial skulls of Zarhachis 

 and Eurhinodelphis are especially worthy of mention, were collected 

 by Norman H. Boss from Miocene deposits along Chesapeake Bay. 



Explorations. — During the summer and early fall of 1923, Secre- 

 tary Walcott, accompanied and aided by Mrs. Walcott, carried on 

 geological field work in the Canadian Rockies in continuation of 

 that of previous j^ears. Special studies were made of the Mons 

 formation of the Ozarkian system, 3,800 feet in thickness, which on 

 the eastern side of the Columbia River Valley was found to contain 

 four well-developed fossil faunas, indicating its position between 

 the Upper Cambrian and Ordovician systems of the geologic time 

 scale. Collections of fossils illustrating! new horizons in the Ozark- 

 ian system were made in this area, also in the Upper Cambrian and 

 Silurian limestones of this region. 



Dr. Charles E. Resser spent August and September in strati- 

 graphic and paleontologic work in the Great Basin ranges of Ne- 

 vada and Utah, the particular object of the trip being to secure in- 

 formation and collections in furtherance of Doctor Walcott's mono- 

 graphic studies. All of the principal ranges of eastern Nevada and 

 western Utah were visited, particular attention being given to the 

 Wasatch and Bear Lake Mountains in the latter State. Of the fos- 

 sils collected many were from entirely new localities. 



Dr. R. S. Bassler was engaged in field work during the season 

 of 1923 in the Central Basin of Tennessee, the Knobstone area of 

 southern Kentucky, and the Niagaran Plain of southwestern Ohio. 



