33. The Crustacea Decapoda of the Lake of Tiberias.’ 
By N. Annanpatez, D.So., F.A.S.B., and Srantey Kemp, 
B.A., F.A.S.B. 
(Plates XII—XIV.) 
Only three species of Crustacea Decapoda have been 
found in the Lake of Tiberias and its immediate vicinity, and 
it is most improbable that any addition will be made to this 
number. 
Two of the three species, namely Atyaephyra desmaresti 
and Potamon potamios, have already been discussed by Barrois * 
in his ‘‘ Liste des Décapodes fluviatiles recueillis en Syrie,’’ 
while the third (T'yphlocaris galilea), by far the most interest- 
ing of the three, was described by Dr. Calman as recently as 
1909. 
Atyaephyra desmaresti has a wide circum-Mediterranean 
distribution and also occurs in some a jacent countries not 
actually on this sea-board; the range of Potamon potamios is 
apparently restricted to the Jordan Valley, lower Egypt and 
the Island of Cyprus, while Typhlocaris galilea is endemic in 
one small pool near the shores of the lake, into which there 
is no evidence that it ever penetrates. 
The last species is of peculiar interest both from a taxo- 
nomic and from a biological point of view, for not only is it 
isolated by its structural characters from all other freshwater 
or marine decapods, but it is apparently modified for a sub- 
terranean existence. The fact that the animal is found living 
in an open and well-lighted pool is, therefore, very strange. We 
may hazard the suggestion that the seismic movements which 
Some change in its mode of life, and that it has been forced 
thereby to abandon the environment by which its special 
modifications were originally induce 
The light cast by the Decapoda on the origin of the fauna 
of the Lake of Tiberias is not a strong one. The onl 
prawn actually found in the lake is essentially a ‘‘ Mediterra- 
1 Published by permission of the Trustees of the Indian Museum. 
® Barrois, Rév. biol. Nord France, V, p. 125 (1892). 
