Trematopy gus | BRITISH ICHNEUMONS. 
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second. Thorax dull; metanotal areae complete or irregular. Abdomen 
usually basally subscabrous on second and third segments ; basal segment 
often somewhat curved, not petiolate, evenly explanate throughout ; 
terebra either straight and short or curved, slender and subexserted; @ 
valvulae curved and usually far apart; hypopygium of d¢ depressed and 
emarginate, of 9 convex, apically rounded and entire. Legs normal and 
somewhat slender. Areolet wanting or triangular. 
In its capital structure, that of the antennae and legs, but especially in 
the very distinct puncturation of the whole body, this genus forms a 
natural link between Zryphon and Mesoletus, differing from both in its 
posteriorly dilated head and from the former in its basally narrower 
abdomen. The genus Rhaestus was erected by Thomson (O. E. ix. 924) 
for the reception of a part of Grypocentrus of Holmgren upon the 
characters :—Palpi short and cheeks distinct, legs not stout, areolet 
sessile, lower basal nervure oblique and distinctly postfurcal ; it was 
placed between Casoglyptus and Mesoleptus (O. E. xix. 1976) but this is an 
untenable position, at least for our species, which has the basal segment 
evenly and strongly explanate throughout, not petiolate, and very little 
longer than apically broad, with antecentral spiracles ; it differs from the 
present genus mainly in its nitidulous body and may temporarily be 
treated of here. 
Table of Species. 
(8). 1. Third segment not impressed; ab- 
domen mainly red. 
(7). 2. Areolet entire ; clypeus not truncate. 
(4). 3. Thorax and abdomen strongly shin- 
ing ; vertex narrow fs .. I. LATIVENTRIS, Holmgr. 
(3). 4. Thorax and abdomen strongly sculp- 
tured ; vertex normal. 
(6). 5. Hind tibiae broadly pure white ; post- 
petiole sulcate = ae .. 2, ALBIPEs, Grav. 
(5). 6. Hind tibiae dull testaceous; post- 
petiole not sulcate 3. ERYTHROPALPUS, Gael. 
(2). 7. Areolet wanting; clypeus apically 
subtruncate ‘ - .. 4. VELLICANS, Grav. 
(1). 8. Third segment distinctly impressed ; 
. only incisures red .. = .. 5. ATRATUS, Holmgr. 
1. lativentris, Holmgr. 
Grypocentrus lativentris, Holmgr. Sv. Ak. Handl. 1856, p. 384, ¢; cf. Rhaes- 
tus lativentris, Thoms. O. E. xix. 1975. 
Somewhat shining and not coarsely punctate with deplanate, mainly 
red abdomen. Head with the vertex narrow, but temples nearly as broad 
as eyes; mandibles red ; clypeus apically broadly rounded. ‘Thorax very 
finely punctate, shining and black ; areola distinct, narrow, parallel-sided 
and shorter than the horseshoe-shaped petiolar area; costulae wanting. 
Abdomen strongly deplanate, bright red with the base and apex more or 
less broadly infuscate ; basal segment very slightly curved, basally narrow, 
explanate throughout, and narrowly subsulcate but not carinate discally 
to centre of postpetiole ; anus explanate, terebra not reflexed. Legs with 
their base, and sometimes the apices of hind femora and tibiae, black. 
