Vol. hes 6.] Crustacea Decapoda of the L. of Tiberias. 249 
[V.S. 
the gill-chamber. As Dr. Calman has pointed out, the margins 
of the carapace are membranous; this feature, combined with 
the horizontal hinge, may well be useful in the direction 
indicated. 
No direct evidence could be obtained that T'yphlocaris is 
subterranean in habits: it is certainly not exclusively nocturnal. 
As nothing is known of the structure of the pool in which the 
animal lives, it is impossible to say whether it can retire under- 
ground; it may do so periodically to breed or for other pur- 
poses, and one of the monks who live at et-Tabghah on one 
occasion searched for specimens for some months without. being 
able to obtain them. No details, however, are available as to 
the methods he adopted. No specimens were seen by Annan- 
ale on a visit paid to the pool early in the morning, although 
the bottom or forming part of the walls. They frequently 
wandered under other stones and sometimes emerged again 
the fairly strong tight that reached and shone through the clear 
water practically without obstruction. An individual living in 
under natural conditions or in captivity, positively so. 
None of the specimens obtained were actually breeding at 
the time they were killed, but the condition of their gonads 
would suggest that the breeding season was approaching. 
he photographs reproduced on plate XII were taken at 
Tiberias by the Rev. J. Cohen of that town under the supervi- 
sion of one of us. We have to thank him for his courteous 
assistance in the matter. 
Family POTAMONIDAE. 
Potamon (Potamon) potamios (Olivier), Rathbun. 
(Plate XIV, fig. 1). 
£1804. Cancer potamios, Olivier (partim), Voy. Empir. Oth., 
IV, p. 240, atlas, pt. 2, pl. xxx, fig. 2. 
