132 BRITISH HYDRACHNID.E. 



the inner side and one on the outer. The apex of two, if not 

 three, of these pegs is furnished with setae. 



Texture. — The cuticle of the body is soft and easily distorted. 

 The legs, palpi, and epimera are hard and chitinous. 



The difference in the male and female is very small. The 

 body of the female is a little more round than that of the male, 

 and the first pair of legs of the female appear somewhat coarser 

 than those of the male ; but otherwise the only noticeable differ- 

 ence is in the genital area. Fig. 4 showing the female, and Fig. 5 

 the male. 



Distribution. — This species may be considered as fairly 

 common. I have taken it on several excursions round London, 

 and found it common on the borders of Llyn Padarn, N. Wales. 

 I found it in the rivers in Suffolk, and have had it sent to me from 

 many other places by collectors. The specimens the drawings 

 were made from were taken by me at Snaresbrook on Sept. 19, 

 1896. They were fine, well grown specimens, but possessed very 

 little colour, the legs and edge of the body being nearly trans- 

 parent. I have always taken it from clear water in ponds and 

 rivers. 



I have kept a quantity of these mites at home alive for some 

 time, but have never yet had any ova deposited in the tubes, so at 

 present the larva is quite unknown to me. In swimming, they 

 swim upwards ; they then extend the legs to the fullest, and rest, 

 as it were, for a few seconds in the water, as if lifeless, then 

 gradually drop towards the bottom. 



EXPLANATION OF PLATE VIH 



Fig. 1. — Dorsal surface of , 9 . 

 2. — Ventral surface of ^ . 

 3. — Ventral surface of $. 

 4. — Genital area of 9 . 

 5. — Genital area of $, 

 6. — Claws of first foot. 

 7. — Palpus of 9 . 



