40 HYDROMETPaNA. 



Bostrum 4-joiDted, curved, reacliing to the first or second pair of 

 coxae; the first joint very stout. Pronotum in front narrow and 

 rounded, or annularly contracted ; disk with a slight transverse in- 

 cision or depression beyond the middle ; the sides also there con- 

 stricted; widened posteriorly. Elytra: Corium, posterior margin 

 straight, well defined; Membrane in the middle, with three long, 

 closed cells, not extending to the margins ; the nerves diverging from 

 them all round, and forming several marginal cells (the clavus and 

 corium sometimes, and the membrane often, but partially developed). 

 Legs : third pair longest ; iliiylis, first and second pair thick, fusi- 

 form ; tihicB, first and second pairs with a spongiose cushion at the 

 extremity. 



Abdomen. — Genital segments, in tlie $ above, 1, trapeziform, broad, de- 

 flected, and projecting ; the sides posteriorly with a contorted process ; 

 beneath 2, the first visible merely as a narrow rim within the sixth ab- 

 dominal segment, the second as on the upper side, but convex, posteriorly 

 roundly deflected : in the § above, 2, the first sliort, not so wide at the 

 base as the sixth abdominal segment, and narrower posteriorly ; the second 

 longer, rounded posteriorly ; beneath, the fifth and sixth abdominal seg- 

 ments are raised up and shortened in the middle, the sixth very short, but 

 broad on the sides ; in the opening thus formed the broad ovipositor 

 occupies the centre ; on each side is the angulated plate of a genital seg- 

 ment, its upward apex covered by the angular, projecting point of another 

 segment. Gen. 1, Metastemma ; 2, Nabis. 



Sub-Div. 2. — Hydrodromica.* 



Section l.—HYDROMETBINA. 



Hydrometrae and Hydroessae, Fleb. 

 Hydrometridea, Flor. 



Structure hard, horny. Form elongate and subparallel, or long- 

 oval. Antenna! inserted on the sides of the head before the eyes, 

 5 or 6-jointedt (the third or third and fifth joints very minute). 



* Page 11. 



t At page 10 the antennae of the Division Gymnocekata are given as 

 3 — 4-jointed, the small intermediate joints in the present section (also in Uebn'na 

 and in Reduvina) not being generally considered to be true joints, but each as 

 belonging to tlie joint immediately preceding it. 



