HUNGERFORD: AQUATIC HEMIPTERA. 55 
KEY TO SUBFAMILIES. 
A. Vertex rather broad. Inner margin of eyes posteriorly emarginate. 
Saldine. 
AA. Vertex narrow. Inner margin of eyes posteriorly subsinuate. 
Saldoidine. 
Subfamily SALDINA. 
Eyes with inner margin posteriorly emarginate. Vertex rather broad. 
Second segment of antenne 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 SALDINA. 
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. 
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 
BB. 
CC. 
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. 
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. 
