a es 
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Vol. LX, No. 1.] he Biology of the Lake of Tiberias. 21 
[N.8.] 
In the short distance (not more than two hundred yards) that 
intervenes between the channel and the southern shore, although 
the water is at some points nearly as deep as the channel itself, 
the sandy clay washed down from the cliffs, which are in a 
state of steady disintegration, interferes to some extent with 
animal life, to which the organic débris deposited immediately 
opposite the village is even more detrimental. Molluscs of the 
genus Melania are fairly common in a living condition in 
the channel just west of Semakh, but only their dead shells 
are to be found in the Jordan itself immediately on its exit 
from the lake. It was in the channel also that I dredged the 
only non-operculate gastropod molluscs seen in the lake, as well 
as the only polyzoon of the genus Plumatella and three of the 
four sponges of the subfamily Potamolepidinae obtained. 
he zooplancton of the lake was not, at the time of my 
visit, abundant or conspicuous in any way. It consisted for 
the most part of minute copepods and rotifers, only a few 
species of each group being represented. ew small muddy 
pools on the shore microscopic life was abundant, but none 
of the larger entomostraca were seen pep 
hironomidae were well represented, as well as adult water- 
beetles and Rhynchota. 
any of the fountains is the blind prawn Typhlocaris galilaea, 
which is only found in one pool among the springs of Tabghah. 
Its habitat will be discussed later in a separate paper. 
ish and mollusca are certainly the most richly represented 
groups in the lake itself. The latter live to a large extent on 
the minute algae that are extremely abundant. The almost 
complete absence of non-operculate gastropod genera is a note- 
worthy feature. The higher crustacea are not well represented, 
the only common decapod being the crab Potamon potamios. 
Several species of the Amphipoda and Isopoda are, however, 
abundant round the edge. 
Except in the small muddy pools already referred to, the 
ime of my visit w 
8 ; 
under stones at the edge of the lake. Only two species of this 
group were, however, observed as adults, and even dragon-flies 
