EASTMAN: REMAINS OF STRUTHIOLITHUS CHERSONENSIS. 131 
valleys, from fifty to a hundred feet deep; but the loess, or yellow clay, has 
been worn away from the greater part of the land north of the Sang Kan River, 
so that sand and gravel predominate. Wherever irrigated by a stream from 
the mountains, the land becomes very good and fertile, Near the eastern end 
of the Hsi Ning valley the Sang Kan River enters a narrow gorge, through 
which it flows ten or thirteen miles to the lower valley of the Pao An. Hach 
of these valleys was once a lake, walled in by the mountains around them. 
The evidence of this is unmistakable. As to the Hsi Ning valley, the Chinese 
say it is recorded in their histories that it was occupied by a lake until about 
the year 1000 A. D., when the waters cut through the mountains, and the lake 
was drained off. The recent date assigned to this event, and the general accu- 
acy of Chinese history, would seem to make the story credible, while the 
configuration of the land shows that such an occurrence must have taken place. 
Now the valley is tilled very carefully, and villages of a hundred families are 
interspersed only two or three miles apart. The soil is mostly poor and grav- 
elly, but the stones in it, heated by the sun, radiate their heat at night, and 
the mountain range on the north is frequently visited with rain; yet the 
climate on the whole is rather arid. 
“ Just north of Yao Kuan Chuang is a remarkable seam of red rock [erup- 
tive dike ?] eighty feet thick, intersecting the mountains in a vertical plane. 
It is very conspicuous in contrast to the brown-colored mountain, and is alleged 
by the natives to be the trail of a serpent, Eight miles west of Yao Kuan 
Chuang is a ridge composed of at roungled pebbles and rock fragments 
[esker ?], which extends from the foot of the northern mountains to the river, 
a distance of about two miles. Farther west are a large number of craters, the 
widest being about two miles in diameter, and containing numerous smaller ones. 
Seventeen miles southwest of Yao Kuan Chuang, on the opposite side of the 
river, is Fu T’ou Chiang, a market for coal, which is brought in large blocks 
on mules from the southern mountains. This coal is of two kinds, one that 
smokes, and one that does not; and the chief peculiarity of both kinds is that, 
if any part of a block gets on fire, the whole will slowly consume away, leaving 
only white ashes. A lump of it as big as a man’s 
ist, if covered with ashes, 
will keep a fire all night.” 
Reference to the works of von Richthofen! and Pumpelly? on the geol- 
ogy of China shows that the above account is in substantial agreement 
with the descriptions of the surrounding region, as furnished by these 
authors. Both of them comment on the desiceation that has taken place 
within comparatively recent times, and note the traces of former shorc 
lines along the mountain sides. The lower part of the Sang Kan flows 
through a synclinal valley, and higher up in its course it drains a number 
of loess basins, from one of which our fossil was derived. According to 
1 Richthofen, F. Fr. von, China, Vols. L.-IIT. Berlin, 1883. 
2 Pumpelly, R., Across America and Asia. 2d edition, New York, 1872. 
