54 BRITISH 
ICHNEUMONS. 
[ Orthocentrint 


Table of Genera. 
late; areolet entire 
areolet often wanting. 
tinct; terebra exserted 
ing; terebra concealed 
. Nervellus vertical, postfurcal, entire ; 
1. Nervellus oblique, antefurcal, genicu- 
ORTHOCENTRUS, Grav. 
3. Hind wing with cubitus basally dis- 
PICROSTIGEUS, 7homzs. 
4. Hind wing with cubitus basally want- 
STENOMACRUS, Zhomes. 
ORTHOCENTRUS, Gravenhorst. 
Gr. I. E. iii. (1829), 358; Thoms. O. E. xxii. 2423. 
Head somewhat constricted behind the eyes, though with the vertex 
often broad ; clypeus apically rounded and covering apices of mandibles ; 
6 face always entirely pale. 
Antennae of @ apically attenuate and 
spiral; @ with basal flagellar joint elongate, linear or cylindrical. Thorax 
with the epicnemia fine, laterally 
distinct; metanotum with four 
longitudinai carinae and the peti- 
olar area distinct. Abdomen with 
the second segment nearly always 
sculptured; terebra nct exserted. 
Hind legs stout with the pulvilli 
usually longer than the claws. 
Wings with the apically straight or 
very slightly curved radial nervure 
emitted from centre of stigma, and 
anal nervure from below centre of 
the brachial cell; areolet entire; 
basal nervure slightly arcuate; hind 
4 Hee eu usS. 
SBupwccres- 

ost. 
wings with the nervellus oblique (not vertical), antefurcal and geniculate, 
usually far below centre. 
The distinctly antefurcal and usually intercepted nervellus distinguishes 
this genus, the species of which are generally larger and stouter, with 
more profuse pale markings than in either of the following. 
Table of Spectes. 
of 9 very large 
(1). 2. Second segment sculptured; 
of normal size. 
. Second segment of 2 smooth; stigma 
: .. I. STIGMATICUS, Holmg. 
stigma 
. Vertex narrow; areolet rarely trans- 
verse; face not granulosely punc- 
2. CORRUGATUS, Holmg. 
tate. 
(5). 4. Vertical orbits pale; 9 postannellus 
linear re te Me 
(4). 5. Vertical orbits never pale; 9 post- 
annellus not linear. 
(11). 6. Frons glabrous below ocelli, of @ 
6 and often @ pale-marked. 
tum black 
7. Areolet distinctly sessile; ¢@ prono- 
3. MARGINATUS, Hlolmg. 
