CEUSTACEA OF LAKE URMI. 395 



AsELLUS, whicli is SO commoa in all European waters, seemed 

 to be entirely" absent in the Urmi basin. It is said to occur in 

 the western tributaries of the Caspian, bat not in Eussiaa 

 Turkestaa or N.E. Persia. 



Amphipoda, 



Gammarus pules, De Geer. 



In the springs near Seir, and also on the other side of the lake 

 in the clear water of a stream near Kirjawa. My observations 

 confirm those of Dr. Walter in regard to the fact that G. pulex 

 seems to prefer the cool, upper, narrow courses of the streams to 

 the warmer, more sluggish, lower reaches in the plains. 



ENTOMOSTRACA. 



COPEPODA. 



A Cyclopid was very common in a pond near Kirjawa, 

 Maragha, but I was not able to determine the species. 



Phtllopoda. 

 Daphnia sp. 



Commou in the stagnaut water of the ditch surrounding the 

 walls of the town of Urmi ; also at Kirjawa. 



AUTEMIA TJEMIATSTA, Sp. U. (PI. 25.) 



The general shape of the body is similar to that of -4. salina, 

 but stouter than in the American species. The males are some- 

 what shorter than the females, in the proportion of 10 mm. to 

 13 ram. The head and " thorax," bearing the eleven swimming- 

 appendages, are very slender, and measured together are nearly 

 equal to the abdomen in length. The segmentation of the abdo- 

 men is so difficult to recognize that I am inclined to regard the seg- 

 mentation as having been partially lost. The first two or three 

 abdominal segments are the only ones clearly distinguishable. 

 The labrum is well developed and is bent over the mouth so as 

 to hide the mandibles. Its distal end is square-ended, with two 

 papilliform processes at the corners; the processes bear small tufts 

 of hairs at their apices, and are probably sensory in function. 



The ventral appendage of the genital segment differs greatlv 

 in the two sexes. In the female it has the function of an ovisac 

 and usually contains ripe eggs. Its shape has been described as 

 resembling that of broad flask. When quite ripe the eggs 



3u* 



