391 WE. R. T. GL'KTHEE OK THE 



CRUSTACEA. 



By EoBEET T. GlJNTHER, M.A., r.E.G.S. 



(Plate 25.) 



MALACOSTRACA. 

 Decapod A. 



Maceuea. 

 I WAS unable to discover that the Crayfish is known from any 

 of the streams that flow into the lake. It is abundant in the 

 Kur. The Syrian zoologist does not differentiate between crabs 

 and crayfish : to him both are ' Kedjala ' and unclean. 



Beachtuea. 



Telphusa eluviatilts, L. 



This freshwater crab is extremely common in all the rivers. 

 They are to be found beneath stones and in little burrows in 

 wet banks. A favourite attitude is sitting half in and half out 

 of the water, so that they are able to pass either air or water at 

 pleasure through tlie branchial chamber. They seemed to be able 

 to employ the openings into the branchial chamber either as 

 exhalant or as inhalant apertures. Indeed, instead of continually 

 propelling water through the branchial chamber in the same 

 direction, they were continually changing the direction, and using 

 the apertures at the anterior margin of the carapace and at the 

 axils of the ambulatory appendages alternately as inhalant and 

 exhalant apertures. 



When sitting regardant, their eyestalks and feelers are set at 

 an angle of 45° with the antero-posterior axis of the body. In 

 colour they are of a greenish-sepia hue, often tending more to 

 green in older specimens, owing to the growth of a green alga on 

 the carapace. The chelae and ambulatory limbs are generally 

 tipped with orange- red, and their sides are often streaked with a 

 purplish tinge. 



The Persian specimens do not appear to differ essentially from 

 those of Italy, Grreeee^nd Palestine which are preserved in the 

 National Collection in the British Museum. 



I s o P D A. 

 Kemileptstfs. 

 Common under stones in damjD places at Seir. 



