224 BRITISH ICHNEUMONS. 
[ Mesoleptus 


basal segment narrow and slender, subelongately pubescent, with central 
spiracles; 9 anus compressed and sometimes entirely testaceous, as is 
always the terebra. Legs red with hind coxae, femora and apices of their 
tibiae usually nigrescent or black; anterior coxae and_trochanters 
flavidous ; hind trochanters flavous, centrally black-marked above ; apical 
hind tarsal joint not half as long again as penultimate. Wings hyaline, 
tegulae flavous, stigma testaceous or flavescent and always pale; areolet 
hardly sessile, apically pellucid below, with fenestrae discreted only by a 
dot ; nervellus intercepted below its centre. Length, 9—11 mm. 
Known from its allies by its slender and more elongate body, but 
especially by the peculiar discal abdominal plaga; the central petiolar 
spiracles will separate it from the species of A/exefer. 
Zetterstedt originally took it in Lapland in July; it is a northern 
species, hardly known outside Scandinavia and probably rarely extending 
south of Scotland with us. It was introduced by Bridgman (Trans. Ent. 
Soc. 1882, p. 155) on the strength of both sexes, taken at Thornhill near 
Dumfries, probably by Dr. Sharp. I have a male and three females; the 
first was swept in July by Elliott at Banchory in Kincardine and mis- 
named by me (E.M.M. 1910, p. 37) JZ. xanthostigmus ; he also took a 
female at Braemar on 19th July, 1907, and Dalglish found others at 
Bishopton and Barr in Ayrshire in July, 1899. In June, rgor, I swept a 
couple of curiously pale females from low herbage in a marshy part of 
Tuddenham Fen; both have the abdomen and legs clear fulvous with 
the petiole and coxae alone black. 
9. testaceus, Fab. 
Ichneumon testaceus, Fab. E.S. Suppl. 1798, 228; Gr. Nov. Act. Acad. 1818, 
p- 285; I. clavator, Schr. F. B. ii. 295, ¢. Bassus testaceus, Fab. Piez. 101. 
Mesoleptus testaceus, Gr. 1. E. ii. 28; i, Suppl. 682; Ste. Ill. M. vii. 216; Zett. 
I. L.i. 387; Boie, Nat. Tids. 1841, p. 323; Holmgr. Sv. Ak. Handl. 1855, p. 101 ; 
Voll. Pinac. pl. 26, fig. 2; Brisch. Schr. Nat. Danz. 1878, p.65, ¢ ?. Mesolcius 
testaceus, Holmgr. Sv. Ak. Handl. 1876, p. 126; Thoms. O. E. xvii. 1885, ¢ ?. 
Var. Mesoleptus melanocephalus, Gr. 1. E. ii. 28; i, Suppl. 682; Ste. Ill. M. vii. 
216, ¢; Zett. I. L.387; Holmgr. Sv. Ak. Handl. 1855, p.100; Voll. Pinac. pl. 
xxvi, fig. 1; Brisch. Schr. Nat. Ges. Danz. 1878, p.65, ¢ 2. Mesoletus melano- 
cephalus, Holmgr. Sv. Ak. Handl. 1876, p.49; Thoms. O. E. xvii. 1884, ¢ ¢. 
Not very shining, entirely testaceous with only the eyes, ocelli, and (in 
var.) frons with the subemarginate occiput to the flavous cheeks, black. 
Head transverse, somewhat short and posteriorly constricted ; clypeus 
subdiscreted, apically depressed and very slightly emarginate ; frons de- 
planate and very finely rugulose. Antennae pale, filiform and subpilose ; 
flagellum with 43—47 joints. Thorax narrower than head and paler 
below, with subhamate flavous callosities before radices ; metathorax very 
finely punctate, pubescent, with no discal areae, and not narrowed 
towards its sinuate and subreflexed apex. Scutellum convex and flavidous. 
Abdomen narrow, with second and third segments longer than broad ; 
spiracles of basal segment distinctly before its centre. Legs slender and 
fulvescent testaceous, with coxae and trochanters paler. Wings ample, 
stigma fulvous; areolet obliquely transverse and petiolate ; nervellus 
intercepted a little below its centre. Length, 8—r11 mm. ~ 
M. melanocephalus has hitherto been considered distinct, on account of 
its darker head, but even Thomson could find no more than colour 
difference. 
