HUNGERFORD: AQUATIC HEMIPTERA. 55 



KEY TO SUBFAMILIES. 



A. Vertex rather broad. Inner margin of eyes posteriorly emarginate. 



Saldinag. 

 AA. Vertex narrow. Inner margin of eyes posteriorly subsinuate. 



Saldoidinse. 

 Subfamily Saldino. 



Eyes with inner margin posteriorly emarginate. Vertex rather broad. 

 Second segment of antennse distinctly longer than the third. Anterior 

 part of pronotum marked by a large transverse oval callosity. This cal- 

 losity often extending beyond the middle. Its disc usually marked by a 

 median foveola. Posterior disc usually marked on both sides by a 

 longitudinal impression reaching to the callosity. Lateral margins en- 

 tirely carinated. 



KEY TO GENERA OF SALDINO. 



A. Pronotum, sides being more or less flattened, front callus never reach- 

 ing to the lateral margins of the sides. Sulcus behind this destitute 

 of punctures and longitudinal wrinkles. Most rarely of all marked 

 with punctures, in this case apex of pronotum almost as wide as 

 head with the eyes. 

 B. Membrane marked with five entire areoles, last ventral seg- 

 ment of female truncate. Pentacora. 

 BB. Membrane marked with four or five areoles of which the sub- 

 external is shorter than the rest, third and fifth more or less 

 contiguous toward the apices. 

 C. Apex of pronotum almost equal in width to the head, a 

 little wider than this. Hemelytra densely and usually 

 distinctly punctulate or subcoreaceous. Posterior tarsi 

 with second and third segments subequal in length, body 

 often wide, membrane usually with five areoles, of which 

 the subexternal one is shortened. Chiloxanthus. 

 CC. Apex of pronotum narrower than head, rarely as wide 

 as this, in this case the hemelytra not punctate. Mem- 

 brane always four-areolated. 

 D. The membrane with its first area or inner base 

 prolonged two-fifths or one-half beyond the base of 

 next area. Hemelytra often punctate, always des- 

 titute of sericeous patches. Embolium entirely 

 black. Salda. 

 DD. The membrane having its first area or inner base 

 prolonged slightly or not more than a third of its 

 length beyond the next area. 

 E. Corium with two entirely distinct veins, inner 

 one furcate toward apex, branches touching 

 the suture of the membrane. First area of 

 membrane or anterior apex usually touching, 

 or nearly touching apex of second. 



Saldula. 



