50 CORIXINA. 



Abdomen flat above, convex beneath : Connexwum at first narrow, gra- 

 dually widened posteriorly, much reflexed, the end projecting. In the $ 

 the last four segments have irregular, unsymmetrical margins ; in the 

 they are regular and parallel, the posterior margin of the 6th concave 

 above, produced triangularly with sinuate sides beneath. Genital seg- 

 ments : The visible parts consist, in the , of two short, contiguous, tri- 

 angular plates, not extending laterally the whole breadth of the last 

 abdominal segment ; beyond these extend two long, broad, flat, oval, side 

 pieces, touching each other posteriorly, reflexed in the same degree as the 

 connexivum, projecting as a continuation of it, and forming the apex of the 

 body : these plates are equally visible on the underside and occupy the 

 whole space beyond the abdominal segments, except that in the middle, 

 close to the base, a small triangle juts through between them. In the $ 

 the visible parts are formed as in the 9 , except that the side plates are 

 not so regular, and the posterior separation is rarely in the middle. The 

 rest of the genital segments and the generative organs are concealed by 

 the plates mentioned. - \ 



FAMILY 1. CORIXIDJE. 



Oblong, subparallel, convex above. 



Head transverse, convex, triangular, liindwardly pointed, sides 

 sinuate, seen from above (including the eyes) lunate. Antennae 

 4-jointed; first and second joints stout, cylindrical; third stout, 

 clavate, as long as the first and second together ; fourth subulate. 

 Pronotum transverse, triangular, pointed hindwardly. Scutellum 0. 

 Metasternum furnished with parapleurce ; the pleurce with a distinct 

 sutural junction. Tarsi, first and second pairs monomerous. Gen. 

 1, Corixa; 2, Cymatia. 



FAMILY 2. SIGARID^E. 



Elliptic, depressed. 



Head triangular, sides subangulated ; seen from above obtusely 

 triangular. Antenna 3-jointed; first and second joints subcylin- 

 drical ; third, oblong, concave. Pronotum transverse, triangular, 

 pointed anteriorly. Scutellum short triangular. Metasternum with- 

 out parapleurse; the pleurae without suture. Tarsi, second pair 

 2-jointed. Gen. 1, Sigara. 



