1897.] Wind River and Bridger Beds. 967 
In May, 1897, the writer accompanied by Dr. J. L. Wortman, 
made a brief reconnaissance of this basin, and came to the fol- 
lowing conclusions; differing from those reached by Professor 
Hills: 
(1) That west of the Huerfano Cañon the variegated marls, 
clays, soft shales and sands aggregate only 800 to 1000 feet in 
thickness, are nearly horizontal in position, and constitute 
alone the true Huerfano Lake deposits. They may be positively 
divided into Upper Beds, equivalent to the Bridger. From 
the observations and conclusions made in the basin there are 
also undoubtedly Lower Beds, equivalent to the Wind River. 
(2) That the so-called Cuchara and Poison Cañon Beds are 
unconformable with the Huerfano and are of older age, prob- 
ably of Cretaceous, as partly determined by the presence of 
Baculites in the Poison Cafion section, which was selected by 
Professor Hills as typical. 
(3) That the eastern boundary of the Huerfano Lake is 
partly indicated in the present cañon of the Huerfano River; 
that this boundary extended to the south so as to include the 
base of Silver Mountain toward the Cuchara Divide; that it 
lies from three to seven miles west of the ‘anticlinal axis’ de- 
scribed by Professor Hills, and that, therefore, the Huerfano 
Lake deposition did not extend as far to the east or south as 
the Spanish Peaks. 
The geological features of these Eina E can hardly be 
dignified by the term “ A theory of the Huerfano Lake,” for 
they were formed during a hasty survey of this basin; while 
Professor Hill’s results certainly deserve the deliberate con- 
sideration of a prolonged survey. In fact this basin with its 
volcanic disturbances and eruptions presents a fascinating 
problem in the geology of tertiary times. Among the Bridger 
forms discovered were many portions of the skeleton of Tillo- 
therium, beside remains of Hyrachyus, Palxosyops, Microsyops, 
Calamodon, Stypolophus and Pachynolophus. This region is 
peculiar in the absence of Uintatherium. In the Lower Beds 
. are found teeth and limb bones of Coryphodon, Lambdotherium, 
Oxyæna, Pantolestes and other Lower Eocene forms, probably of 
Wasatch age. 
