Mesolevus | BRITISH ICHNEUMONS. 147 

flavidous or fulvo-stramineous. Antennae with flagellum testaceous be- 
neath. Thorax elongate, with flavidous callosity before radices and 
notauli extending to apex; mesopleurae alutaceous, nitidulous and very 
finely punctate; metanotal areae incomplete. Abdomen more or less 
broadly red centrally ; basal segment narrow and only slightly longer than 
hind coxae, with its basal fovea minute and discal sulcus evanescent, of 
Q rarely red. Legs red, with anterior coxae and trochanters partly 
black ; hind legs black with their tibiae broadly red at the base. Wings 
with stigma flavidous, radix and tegulae stramineous; areolet complete, 
distinctly petiolate; nervellus subopposite. Length, 8—9 mm. 
I do not think this species is synonymous with Thomson’s JV. (A/exefer) 
fallax of O. E. xix. 2025, which he places next after A/esolep/us ruficornis, 
Grav. (O. E. xvii. 1885), since he says the face in both sexes is flavous 
and the conformation of both his species similis et affinis. At all events 
the British representatives are true J/esoler?, superficially resembling JZ. 
semicaligatus in the conformation of their basal segment. 
This species was introduced as British by Bridgman (Trans. Ent. Soc. 
1881, p. 164) on the strength of three males recorded by Dr. Capron from 
Shere in 1879 (Entom. 1880, p. 88); these are now in my collection and 
differ from JZ. semicaligatus in little but the pale anteradical callosity. 
Tuck sent me an analogous example on 7th October, 1899, taken by him 
in Norton Wood, near Bury St. Edmunds. Bignell records this species 
in 1898 from Laira, Plymouth and Bickleigh in Devon during June, July 
and August. Elsewhere it is known from Prussia, Sweden and France. 
10. erythrocerus, Grav. 
Tryphon erythrocerus, Gr. I. E. ii. 230, cf. i. 689; Steph. Ill. M. vii. 247, ¢ ¢. 
Bassus erythrocerus, Zett. Ins. Lap. i. 380, ¢. Mesoletus erythrocerus, Holmgr. 
Sv. Ak. Handl. 1855, p.166; Brisch. Schr. Nat. Ges. Danz. 1892, p, 34; M. 
(Lagarotus) erythrocerus, Thoms. O. E. xvii. 1882, ¢ ?. 
Head with vertex broad, a little constricted posteriorly, cheeks hardly 
buccate, clypeus apically not depressed but centrally emarginate, discally 
deplanate with small foveae; @ with mouth and face flavous. Antennae 
black, apically dull red; scape of g flavous beneath. Thorax oblong and 
immaculate; mesonotum nitidulous and finely punctulate with very 
obsolete notauli; metathorax apically constricted, rugulose with areae 
more or less distinct, the petiolar small, not reaching beyond the apical 
third, sometimes incomplete. Scutellum black. Abdomen oblong and 
lateratly subparallel, black with second and third segments, except apex 
of latter, red; basal segment nearly twice longer than apically broad, 
apically subdilated, discally subrugosely punctate, laterally pilose, with 
basal scrobes deep; second somewhat shining, hardly shorter than broad 
and transversely convex; anus almost compressed, terebra black. Legs 
slender and black with the anterior tibiae, the front femora except basally 
and the intermediate apically, red ; hind tibiae, except apically, red; @ 
with anterior trochanters and apices of coxae pale. Wings hyaline with 
stigma narrow and pale; ¢@ tegulae pale; basal nervure a little oblique, 
areolet small and sometimes almost wanting ; nervellus opposite and inter- 
cepted below centre. Length, 7—8 mm. 
Pfankuch says that the above description agrees with the types and 
adds that the basal segment is broader and shorter than in JZ. semica/t- 
gatus, finely rugose-punctate, and flavous-red margined, the second and 
K2 
