ae 
British Hemiptera-Heteroptera. 139 
©. Thorax constricted in the middle in a waist- 
like manner .. oe 56 55 a 
CC. Thorax not constricted in the middle in a 
waistlike manner. 
a. Head exceedingly wide, eyes longly pe- 
dunculate.. oe oe ee a 
b. Head not so wide, eyes not pedunculate. . 
BB. Sides of the thorax with a well-defined lateral 
margin. 
. Membrane without cells. 
. Side margins of thorax foliaceous, or with a 
sharp leaf or knife-like edge throughout 
their length, often wider and pale near the 
middle, never thickened or narrowly re- 
Ya 
flexed. 
E. Thorax with long hairs all over or only round 
the front margin .. oe ata oe 
EE. Thorax without long hairs. 
F. Front margin of thorax constricted into a 
very short, sometimes raised collar. 
a. 1st joint of antenne as long as second .. 
b. Ist joint of antenne much shorter than 
2nd an oe ee +e ee 
FF, Front margin of thorax not collared or raised. 
G. Basal joint of intermediate tarsi longer than 
2nd and 3rd together. 
H. Eyes prominent, projecting beyond the sides 
of the thorax Se oe as “ie 
HH. Eyes not prominent. 
I. Antenne covered with bristly black hairs .. 
If. Antenne not covered with bristly hairs .. 
GG. Basal joint of intermediate tarsi shorter than 
2nd and 38rd together oe wie «rs 
DD. Side margins of thorax not flattened or leaf- 
like, often raised or reflexed or thickened. 
HE. Sides without lateral carine .. ee Se 
EE. Sides with lateral carine. 
F. Lateral carine visible from above. 
G. Species linear, parallel sides (elytra almost 
always undeveloped). 
a. 8rd joint of rostrum as long, or nearly as 
long, as 2nd; 2nd. and 3rd abdominal 
segments above much and angularly 
produced posteriorly ; the apex of the 
angle widely truncate .. “0 ye 
b. 8rd joint of rostrum much shorter than 
2nd and 3rd, abdominal segments very 
slightly angulated, the apex of the 2nd 
very finely truncate a oe a 
GG. Species not linear and parallel-sided. 
H. Thorax more or less constricted (although 
sometimes very slightly) at or behind the 
middle, transversely impressed and punc- 
tured, 
Plociomerus. 
HHenestaris. 
Nysius. 
Eremocoris. 
Notochilus. 
Scolopostethus. 
Dieuches. 
Emblethis. 
Calyptonotus. 
Trapezonotus. 
Tropistethus. 
Macrodema. 
Ischnocoris, 
