BEETLES. 3:? 



smooth wing-cases. The scuteUum is rusty-red, and the 

 appendage of the metasternum is narrow and pointed. It is 

 found in ponds and ditches, but is not common. 



* T). piindulatus, Fabr. (Plate IV., Fig. 12). Metasternum 

 produced behind into two blunt and rounded processes. It is 

 chiefly found in running water, and is common and widely 

 distributed. 



Genus Acilius, Leach. 



Body oval, slightly convex. The appendage of the pro- 

 sternum is rounded at the end. The front tibise of the males 

 are expanded and flattened. They are found in any kind of 

 standing water. 



* A. sulcatus, Linn. (Plate IV., Fig. 13). Shortly ovaL 

 Wing-cases with four broad, hairy furrows in the female. 

 It is common in lakes and ponds. 



Genus Hydaticus, Leach. 



Slightly convex species, elongated ovate. The projection on 

 the prosternum is rounded at the end. The males have pulvilli 

 of nearly equal size on the under -surface of the tarsi. The 

 wing-cases are not furrowed in the females. They are of 

 moderate size, and may be found in ditches, swamps, and 

 stagnant water generally. 



* H. tra7isversalis, Fabr. Has a length of about 13 mm.. 

 It is black, with the anterior and lateral borders of the 

 pronotum ferruginous. The wing-cases are broadly bordered 

 with yellow, and there is a narrow transverse band of the 

 same colour at the base. The middle tarsi of the males 

 have three expanded joints, and are provided with pulvilli 

 beneath. 



