Geology and Mineralogy. 491 
this he wails lake-liss. The lakes had formerly sag width than 
now; and in the valley of the Wei where the true léss is oe 
sive,. “he has seen it overlying the laminated lake-los ss. Abou 
the ‘dried-up basins, under the present dry climate, salt aoe 
cences are common. 
From all the facts he concludes that the léss-basins were 
originally sites of salt lakes; that the land had less height in the 
interior to the northward than now, as shown by the succession of 
liss basins going west, and that the basins had consequently very 
great extent ; that the climate was so dry that the evaporation | 
exceeded the fall of wat er, and consequently the streams were 
very feeble, or dried up, an nd that this was another occasion for 
great undrained basins; that the true léss was formed about the 
dry borders of the basins by the methods above mentioned, and 
gradually spread inward covering the lake-léss as the water of the 
basin diminished, so giving the upper surface of the deposit a 
was much like the present state of ‘be salt-steppes of Central 
Asia; and that the léss-making era was brought to an end de a 
change of climate in which gr reat rains chan nged ‘08 rivers 
floods, which led to their cutting channels through Ky basins a 
opening up the present system of drainage. Thus the Hoang-ho 
this drainage a ag was promoted also by an elevation to the 
ev 
a eapenil?s article, referred to "a was peace 
ne a perme of Baron von Ri chthofen’ s views; and it is of inter- 
est here s arguments. ost important are these: 
that the disintegration going on over the hills is a very inadequate 
source o r such great and thick deposits, and the winds 
made, Pe p 
von Richthofen’s, yes 
Pekin and about Kalgan) for the freshwater and lacustrine origin of 
the liéss from the presence of shells in the deposits (at Té Hai) ; 
rom the uniform constitution and fineness of the liss, this “ prov- 
ing that it has not come from what were the neighboring shores, 
but that it*was brought into the lakes by one or more large = 
which must have drained an area of great extent. J.D 
2. International Geological Congress,— The nu mber of shis 
Journal for December of 1876 contains the announcement of the 
