ARADIDAE IIEBRIDAE HYDROMETRIDAE 



SSI 



breast, so that the rostrum is free. Of the five species, three 

 occur in Chili and Patagonia, two in Tasmania, and one in 

 Australia. 



Fam. 8. Hebridae. — Minute bugs, of semiaquatic habits, 

 clothed beneath with a dense, minute, silvery pubescence; antennae 

 fire-jointed ; legs of not more than average length; elytra in larger 

 part membranous. — This small family consists altogether of only 

 about a dozen species ; we have two species of the genus Sehrus 

 in Britain ; they are usually found in very wet moss. 



Fam. 9. Hydrometridae. — For7n very diverse ; antennae 

 four-jointed, tarsi two-jointed. Coxae tisually widely separated. 

 Either wingless or with elytra of one texture throughout, having 

 no membranous part. Under sitrface with a minute velvet -like 

 pubescence. In many forms the legs are of greeit length. — Although 



of comparatively small extent — scarcely 200 species being at 



present known — this family is of great 



interest from the habit possessed by its 



members of living on the surface of 



water. In the case of the notorious 



genus Halobates (Fig. 265) the Insects 



can even successfully defy the terrors 



of Neptune and live on the ocean 



many hundreds of miles from land. 



There is great variety of form among 



Hydrometridae. The European and 



British genus Mesovelia is of short 



form, and but little dissimilar from 



ordinary land-bugs, with which, indeed, 



it is connected by means of the genus 



Hebrus, already noticed. Mesovelia 



represents the sub-family Mesoveliides, 



which, though consisting of only four 



species, occurs in both hemispheres, and 



in the tropics as well as in the tem- 

 perate regions. Our species, If.furcata, 



walks on the surface of the water, the 



movements of its legs and the posi- 

 tion of its coxae being those of land -bugs. Another British 



Insect the highly remarkable Hydrometra stagnorum — is of 



excessively slender form, with long thin legs, by aid of which it 



Fig. 265. — Halohates sobrinus. 

 Under surface of a female 

 carrying eggs. Pacific Ocean 



(Marquesas). 



