1918] 
Barber—Synoptic Keys to the Lygvide (Hemiptera) 81 
and several smaller teeth distributed along almost entire 
length. Clavus with three rows of punctures, the middle 
series abbreviated. Macropterous forms only. 
Peritrechus Fieb. 
CC. Pronotum with both lobes concolorous or nearly so, most 
commonly ferrugineous or castaneous, rarely black, most 
commonly shining or somewhat so. Scutellum not bivit- 
tate with pale. 
D. Third ventral suture of the abdomen straight and reach- 
ing the lateral margin. Head across eyes distinctly 
narrower than anterior margin of pronotum. Pronotum 
with lateral margins more or less strongly keeled, with 
impunctate anterior lobe as wide or wider than the much 
shorter posterior lobe. Scutellum subtransverse. Clavus 
broad, not deflected to the corium, sometimes connate 
with the corium. Membrane usually abbreviated or 
wanting. Only brachypterous forms known to me. 
Plinthisus Latr. 
DD. Third ventral suture of the abdomen curved anteriorly 
and not reaching the lateral margin. Head across eyes 
as wide or most commonly wider than the anterior margin 
of the pronotum, most frequently as wide as across 
rounded submargin. 
E. Pronotum with both lobes very distinctly and closely 
punctate and at the same time with the lateral margins 
evidently carinate. Scutellum longer than wide. Fore 
femora unarmed. 
F. Lateral margins of pronotum more strongly carinate. 
Eyes more projecting. Pronotum and hemielytra not 
pilose. Clavus with three rows of punctures. 
Acompus Fieb. 
FF. Lateral margins of pronotum narrowly carinate. Eyes 
less projecting. Pronotum and hemielytra pilose. 
Clavus with four series of punctures. 
Stygnocoris D. and S. 
EE. Pronotum with the entire anterior lobe or the disk only 
impunctate; lateral edge either very finely carinate or 
the propleura linearly and longitudinally impressed 
within the ‘lateral margin. Scutellum equilateral. 
