1915.] Matthew and Granger, Lower Eocene Wasatch and Wind River Faunas. 3 
(3) Black Buttes (margin of the Washakie Basin) Wyoming. A few - 
fragmentary Wasatch fossils obtained in this vicinity by Cope in 1872 and 
by Marsh a few years later. No subsequent collecting. 
(4) Wind River Basin, Wyoming. A valuable collection obtained by 
Wortman for Cope in 1880, including the famous Hyracotheriwm venticolum 
skeleton. Wortman obtained a number of specimens for the American 
Museum in 1891 and again in 1896. In 1904 Dr. Loomis led a successful 
expedition for Amherst College, and in 1905 and 1909 the formation was 
systematically searched by Granger for the American Museum and large 
although mostly fragmentary collections obtained. Wortman’s collections 
were made in the upper levels of the formation, Loomis’s in the lower 
horizon; Granger’s material is from all the fossiliferous horizons. 
(5) Big Horn Basin, Wyoming. This is by far the richest region for 
Wasatch fossils, the beds being extensively exposed and fossils often fairly 
common, although rarely complete or perfectly preserved. It was dis- 
covered by Dr. Wortman in 1881 and a large collection obtained for Pro-.. 
fessor Cope including the famous skeletons of Phenacodus. In 1884 a. 
party from Princeton University obtained a small collection. In 1891 and 
1896 Wortman again explored it in the interests of the American Museum. 
obtaining many valuable specimens. In 1904 Loomis obtained a consider-. 
able collection for Amherst Museum. In 1910, 1911 and 1912 Granger 
searched the formation systematically with great success, his collections. 
exceeding in amount and value all those previously obtained. In 1913. 
Mr. Stein completed the exploration of the basin under Granger’s direction. 
6. Clark Fork Basin. <A small basin adjoining the Big Horn to the 
northwest, but draining independently into the Yellowstone River, and 
apparently semi-distinct in its Lower Eocene deposition. It was visited by 
Wortman in 1896, but the first fossils of any importance were obtained by 
Granger in 1911-12 and by Stein in 1913. The earliest Wasatch and sub- 
Wasatch beds are best represented in this basin, containing many new and 
primitive species herein described. | 
Most of the above collections are in the American Museum; the re- 
mainder in the National, Yale, Amherst and Princeton museums. I do 
not know of any other Lower Eocene fossil mammals in this country, save 
for a few specimens from the Uinta Basin in the Carnegie Museum at 
Pittsburgh. A number of field parties of the U. 5. Geological Survey have 
made important contributions to our knowledge of the stratigraphy of these 
Lower Eocene formations, but none so far as I am aware have obtained any 
considerable collections of their fossil vertebrates. 
From the lower Eocene (Suessonian) formations of England, France and 
Belgium a small mammalian fauna has been obtained. It is closely allied 
