224 MODERN STSTtM. 



Fam. IV. HvDROMETiD.E. Leath. 

 CiMiciDES I. 2. Lutreille. 



Rostnini with two or three disthict joints : labriim very fchort : eyes 

 moderate : feet very long, Conned for walking on tiic water, with the 

 nails very minute, inserted laterally into a fibs ure at the extremity 

 of the last joint of the tarsi. 



Genus 282. HYDRO^.IETRA. Ltttr.,Lam.,Tohr., Leaeh. Cimex. 

 Linn., Geo[f\ Aquauics. Se/ie//enberg. 

 Anlen?ies setaceous, the third joint longer than the rest: anterior feet 



simple: /ry/^/ elongute-cylindric, apex thickened. 

 Sp. 1. Hyd. stagnant nt. Black above: feet brown reddish, 

 llydrometra stagnoruni. Fahr., Leac/i. Cimex gtagnorum. Linn. 



Aquarius paludum. Sc/iellenkrg. 

 Inhabits Europe in most places, and walks on the surface of the water. 



Genus 283. \'ELIy\. Latr., Leach. Cimex. Rossi. Hydrome- 



TRA. Fabr. 



Anfcnno' hViform, the first joint longest: ««^t;?-''or ^tr? raptorious : 7os- 

 ^/■«/« two-jointed : /)a«/ somewluit vertical. 



Sp. 1. Vel.rividorum. Black; sides of the thorax and margins of the 

 abdomen red : thorax with two anterior punctures ; each elytron 

 with three and a spot of white; inferior sides ot the abdomen punc- 

 tured with black. 



Hydronietra rivulorum. Fnhr. \^elia rivulorum. Latr., Leach. 



Inhabits running waters and springs. 



Genus 28i. GERRIS. JMtr., Leaeh. Ci.mex. Linn., De Ceer, 



Sc/trank, Geoff". 



Antcnnir filiform, the first joint longest, the last cylindric: anterior feet 

 raptorious : rostrum three-jointed : head porrected. 



Sp. 1. Ger. paludum. Brown-olive, black above, cinereous, silky be- 

 neath : abdomen nearly equally broad : truid'C as long as the head, 

 carinated beneath, a series of impressed lines on each side : antennas 

 and feet black : thorax with an elevated line extending to the middle 

 of the back : lateral margins of the thorax and abdomen with tlie 

 anus reddish. 



Hydrometra paludum. Fabr. Gerris jxiludum. Latr., Leach. 



Inhabits ponds and ditches in France, England, and Sweden. 



Oks. — The species of this genus are certaiidy but little known ; ths}' 

 arc either subject to great variation, or are very numerous. 



Fam. V. AcANTuiD.i. Leach. 

 CiMiciDES II. Latreille. 



Lahrum very prominent : eyes very large : feet formed for walking and 

 jumping. 



