62 



THE SCOTTISH NATURALIST 



and Viets have noted for the male and female respectively, a 

 thorn-shaped process near the outer end of the posterior margin. 

 In one of the plates of my specimen, this occupies what is apparently 

 the normal position, while in the other it is half-way along the 

 margin. 



The genital shield lies between the fourth pair of epimera, and 

 extends beyond them posteriorly for about one-third of its length. 

 It is cordate in outline, with an anterior \/-shaped c ^ 1 extending 

 in for about one-third of the length. The two anterior lobes are 

 closely covered with small acetabula. The posterior portion is 

 minutely porose and fringed with relatively coarse hairs. The 

 posterior median portion of the shield forms a canal adapted to 

 the branched chitinous structure (petiisgeriist) functioning as a 

 sexual organ, which in my specimen has the anterior branches much 

 larger than Koenike's figure would seem to indicate. 



The legs are long and strongly built, but the claws are small 

 and simple. Swimming hairs are present and in addition to, and 

 in some cases equalling them in length, are a number of stiff 

 plumose bristles ranged along the middle segments of the legs. 



Hydrarachna levis 9 > epimera and genital area. 



Hydraraclina levis, nom. nov. 



1908. Hydrachna levigata, Soar. J. Quekett Club, Ser. 2, x. 276-7. 



In noting this species as an addition to our fauna under H. 

 levigata, the recorder appears to have been misled by the entire 

 absence of papillae, which up till now distinguished H. levigata 

 from the other members of the genus. The specimen came into 

 my hands at a later date for examination, and I then discovered we 



