fe 
— here water is the principal agent as it continually carries 
away the products of erosion by the rivers. 
As regards Turkestan”, MusHKETOW maintains, contrary 
to RICHTHOFEN, that this part is very similar to Central Asia 
proper. It is without drainage to the sea and the eolian or 
windborne deposits are the most important feature. The 
rivers in the lowlands have no effluence, and can therefore 
only be local agents in transportation. Moreover there is a 
very close geological affinity, deposits from the Cretaceous and 
Tertiary periods stretching, almost without interruption, from 
Hanhai into Turkestan, not only through the ravine of Dsun- 
garia but also more to the south. Hanhai and Turkestan 
have been covered by the same Tertiary sea. 
MUSHKETOW therefore, for the present at any rate, rejects 
RICHTHOFEN’S definition of Central Asia and designates as Asia- 
Media the regions that are without drainage to the open sea 
and amongst these Turkestan. (1. ce. p. 11). 
Turkestan or the Turkestanian Basin, called by Roma- 
NOWSKI the Turanian Plain, is defined by MusHKETOW as 
follows: It stretches from the Mugodshar mountains and 
Usturt in the west to Tsungei Alatau, Thianshan and Pamir 
in the east, from Kopetdagh and the Chorassan mountains 
in the south, to Tarbagatai and Tjingistau in the north-east 
and in the north to the watershed between this area and the 
rivers running into the Irtish. (See the map appended to 
this memoir). The mountain range Karatau divides the area 
into two parts: the north-eastern Balchash Basin which is 
not dealt with here except as regards the distribution of 
plants, and the Aral Basin or the Turanian Basin proper. 
This latter is the subject of the present contribution, 
but not to the full extent of the limits given above. In view 
of the botanical investigations, it is advisable to fix the nor- 
thern boundary in this memoir at about 46° N. Lat. This 
line passes through the northern part of the Aral Sea and 
thus cuts off the whole territory of the Kirghiz Steppe. The 
*) Mushketow also discards East Turkestan as name of a geographical 
area on the ground that it belongs to the Central region of Asia 
(L. c. p. 13). 
