Vol. a 0. 6.] Crustacea Decapoda of the L. of Tiberias. 245 
YS] 
Family PALAEMONIDAE, 
Subfamily TYPHLOCARIDINAR. 
Typhlocaris galilea, Calman. 
(Plates XII, XIII.) 
1909. T'yphlocaris galilea, Calman, Trans. Linn. Soc., Zool (2), 
XI 93, pl. xix. 
? 
e are in entire agreement. The differential characters of the 
Typhlocaridinae may be briefly stated as follows :— 
The small and feebly developed rostrum. 
The palpless mandible. - 
The rudimentary condition of the additional ramus of 
the outer antennuJar flagellum. 
The undivided distal endite of the maxilla. 
The presence of a pair of longitudinal suture lines 
on the carapace, recalling those found in certain 
Reptantia and Penaeidae. 
In the first of these characters, the subfamily agrees with 
some Pontoniinae and Pa'aemoninae; in the second with all 
members of that subfamily and with some Palaemoninae; in 
the third with the Palaemoninae more than any other subfamily. 
In the fourth and fifth characters T'yphlocaris differs, so far as 
is known, from all other Palaemonidae. 
As 
CO DS 
es 
we are inclined to regard the resemblance between them 
as convergent rather than of genetic origin. : 
It is difficult to say in all cases what are the functions of 
the common characteristics, but it is noteworthy that those 
genera of Pontoniinae (Pontonia, Conchodytes and Typton), in 
which the rostrum is reduced, are, at any rate in most cases, 
of semi-parasitic or symbiotic habits and live in enclosed spaces. 
Nothing is known of the mode of life of the two species 
Euryrhynchus yet described, except that they have been found 
m wells, into which it is probable that they have made their 
way from some subterranean reservoir. T'yphlocaris galilea, as 
