VIII ARADIDAE — IIEBRIDAE HYDROMETRIDAE 5 5 I 



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 hugs, of semiaquatic habits, 

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

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

 fart membranous. — This small family consists altogether of only 

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

 in Ik'itain ; they are usually found in very wet moss. 



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

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

 Either wingless or with elytra of one texture throtighout, having 

 no membranous ixtrt. Under surface with a m^inute velvet -like 

 pubescence. In many forms the legs are of great 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- „ „^^ -nr , ^ . 



.■^ . i!\G. 265. — Halobates sohrinns. 



perate regions. Our species, M.furcata, Under surface of a female 

 walks on the surfece of the water, the ^^"^^^s ^'-f • ^'^"'^'^ ^^^^^^ 



' _ (Marquesas). 



movements of its legs and the posi- 

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

 Insect — the highly remarkable Hydromctra stagnorum — is of 

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



