458 Journ. of the Astat, Soc.of Bengal. [Nov. & Dec., 1915. 
contempta, Dtz.) has been found beyond the immediate 
vicinity of the lake ; it is, so far as we know, endemic 
in Palestine and Syria. Of the remaining four, three (B. 
syngenes, B. galilaeae and B. vexillum, Preston) are only known 
from small pools or streams on the shores, while the fourth 
(B. annandalei, Preston) has been found both in a small pool 
and at the edge of the lake. 
and may very easily have been overlooked in other localities. 
A prolific evolution of species seems to be characteristic of 
the family. Neither the species nor the genera of the Lake of 
Tiberias provide any clear indication of the origin of the fauna, 
but both may be said to have a Palaearctic facies and neither 
would by themselves necessarily indicate tropical affinities. 
VALVATIDAE, 
which also been taken at several localities in Syria. 
Valvata is widely distributed in the Northern Hemisphere and 
a@ common European species is sai i ashmir.! 
NERITIDAE. 
The Neritidae are represented in the Jordan system by 
several species of the genus or subgenus Theodoxis, Montfort. 
‘abundant in almost every stream and spring throughout the 
whole of Palestine, east and west.’’ It is probably an 
4 
; 
q 
