Vol. were oe: & 11.] The Fauna of the Jordan System. 471 
Or 
& 
a 
oe 
IV. 
supposing that the outlet of the Lake of Tiberias 
and possibly other parts of the system may at a 
rt 
including a few species that appear to be of Nilotic 
origin. 
The northern and eastern Palaearctic animals, in cases 
in which they had no powers of independent progres- 
sion on land, probably reached the system through 
floods or other occasional agencies. 
The Nilotic species are mostly amphibious and may 
have arrived on their own feet or wings. They 
geographical sections. 
This phenomenon is also illustrated in another direc- 
tion by certain species that occur both in the Jordan 
Valley and in North Africa, but are absent from 
has been utilized by vigorous species of Ethiopian 
origin which have ousted their less vigorous endemic 
relatives. 
SOME OF THE. MORE RECENT AND MORE 
IMPORTANT WORKS ON THE AQUATIC 
ANIMALS OF THE JORDAN SYSTEM. 
GENERAL. 
Annandale .. ‘‘ Introduction to a Report on the Biclogy of 
the Lak 0c. 
e of Tiberias.’’ Journ. As. 
_ «The African Element in the Freshwater 
Fauna of British India,’’ 1X Congres 
internat. de Zool. Monaco, pp. 579-585 
(1914). 
