438 Journ. of the Asiat. Soc. of Bengal. [Nov. & Dec., 1915, 
which arises in large swamps in the desert east of Damascus. 
To the south the Dead Sea is separated by a considerable 
stretch of dry desert from any other body of water. The greater 
part of the Jordan system lies considerably below sea-level. 
eographical isolation of the Jordan would lead us, 
had it existed for any considerable period, to expect a much 
greater degree of specialization in the aquatic fauna than is 
actually found; but there is much evidence that in late Plio- 
cene times that river was directly connected with the Indian 
cean and with some of the African systems. This evidence 
is ussed in the third part of the present paper. The low- 
lying sheltered position of the greater part of the Jordan 
Valley has produced an almost tropical climate and is perhaps 
to some extent the cause of the richness in species, more particu- 
larly in molluscs and fish, of the aquatic fauna. 
The water of most of the system is more or less brackish 
or salt—a factdirectly due to its geographical peculiarities. 
The salinity, however, is not sufficiently intense to have had any 
very great ” sflect on the fauna, except in the Dead Sea, the 
water of which is poisonous as well as being strongly saline. 
The name of this lake expresses a literal fact. 
The Jordan is connected also with two other lakes, through 
both of which it flows. These are L. Huleh, anciently known 
as the Waters of Merom, and the Lake of Tiberias or Sea of 
Galilee. The former, which is about 5 miles long and 3 ae 
in greater detail in Barrois’s Treatise on the Lakes of Syria: 
The lake is about 14 miles long and diskshly nowhere more than 
about 50 metres deep. Its. water, though distinctly brackish, 
is drinkable, the salinity being* ‘*536 parts per million and 
the specific gravity 1-00043 9) or 0°99775 (2 = in vacuo).”” 
I. LIST OF THE AQUATIC FAUNA OF THE 
7 TIBERIAS BASIN. 
of which the names are marked with an asterisk are app®! 
ies 
ently endemic in the Jordan he aducaes those forms whose names bear 
a dagger, in Syria and Palestin 
Porifera, 
Bane fluviatilis syriaca,t Nudospongilla wa to Annan- 
dal 
N wdosponils reversa,* An- e prim Brey 
Corlispongilla barroisi* (Topsent). 
a Rev. Biol. N Nord France VI, 
p- 224 94). 
? Christie, Journ. As. Soc. B Bengal. rhe s.) IX, p. 26) (1913). 
