HYDROMETRINA. 41 



Eyes at the base of the head, rather large, hemispherical, promi- 

 nent. Ocelli or 2, very small and indistinct. Bostrum 3 — 4- 

 jointed. Pronotum united to the Mesonotiim, posteriorly produced 

 in a scutellar form. Scutellum wanting. Elytra of a hard, uniform 

 consistence throughout, not divided into Clavus, Corium, and Mem- 

 hrane, traversed longitudinally by strong nerves, which anastomose 

 in places, and so form closed cells. (The Elytra and wings are 

 sometimes but partially developed, sometimes wholly wauting.) 

 Sternum flat or convex. Legs : Coxce of the second and third pairs 

 inserted at the sides of the sternum ; second pair of legs usually the 

 longest ; tarsi 2 — 3-jointed, the last joint with two fine claws in- 

 serted before its apex ; Puhilli wanting. 



Abdomen. — In both sexes six abdominal segments visible ; the Genital 

 segments vary in the genera as stated. 



Family 1.— HYDROMETRIDtE. 



Long, narrow. Head long, 5-sided, curved ; Face, central lobe 

 prominent. Antennce inserted on a horizontal process at the sides of 

 the head, 5-jointed ; the third, minute. Eyes large, globose, close to 

 the pronotum. Ocelli small. Postrum reaching to the first pair of 

 coxse, 4-jointed ; first and second joints short, third very long. Pro- 

 notum long, 5-sided, in front depressed, sides subparallel ; the sides 

 towards the binder angles mostly incrassated and raised into a tu- 

 bercle, the margin turned under ; scutellar process triangular. Ely- 

 tra flat, nerves strong, forming five long closed cells. Sternum convex, 

 rather wider than the pronotum ; Mesosternum very long. Legs : first 

 pair short, second and third pairs long, thin ; Coxce, first and second 

 pairs inserted in a horizontal projecting sheath posteriorly on the 

 sides of the meso- and metasternum ; Thighs, first pair stout, 

 somewhat flattened ; second and third pairs long, cylindrical ; tihice, 

 first pair stout, obtuse ; second and third pairs long, filiform ; 

 tarsi, first pair stout, short ; second and third pairs very long, fili- 

 form ; claios short, the base covered by a projection of the upper 

 side of the last joint of the tarsus. 



Abdomen very convex beneath ; Connexivum broad, reflexed, on the sixth 

 segment produced into a long and sliarp or a triangular point. Gen. L 

 Hydrometra. 



