36 BEETLES 



Genus Philhydrus, Sol. 

 Body elongated, oval. Antennae with nine joints, with the 

 second conical. Only the mesosternum is keeled. The hind 

 legs are only slightly compressed. These beetles are found in 

 standing water. 



* P. lividus, Forst. (Plate IV., Fig. 19). This is a moderately 

 convex, brownish-yellow beetle. The wing-cases are without 

 an impressed sutural line. It is a common species. 



Genus Laccobius, Erichs. 



Body small, almost hemispherical. Antennae with eight 

 joints, with a long three-jointed club. The hind legs have a 

 row of swimming hairs on the upper surface. They live in 

 standing water, at the roots of aquatic j)lants. 



* L. minuhcs, Linn. Only 3-4 mm. in length. Elytra 

 greyish-yellow, spangled with black, closely punctate-striate. 

 It is not common. 



Genus Berosus, Leach. 



Body elongated, oval. The wing-cases are deeply punctate- 

 striate. The hind tibioe and tarsi are ciliated. They live at 

 the roots of plants growing in standing water. 



* B. luridus, Linn. This is a very convex, dirty brownish- 

 yellow insect. The wing-cases are generally spotted with 

 darker, and terminate in a point. Length, 4-5 mm. It is- 

 found in pools, but is local. 



Genus HELOniOEUS, Fabr. 



These are for the most part longish, oval little beetles, with 

 nine joints to the antenme, the last three of which are en- 

 larged. The thorax has five longitudinal furrows. They live 

 on the margin of standing water. 



