Mesochorus] BRITISH ICHNEUMONS. • 327 



on the frons above the scrobes white; the hind tibiae basally and above 

 at their apices black, the hind tarsi pale, and apices of the transverse 

 second and of the following scgmenls narrowly whitish, as in the last 

 species, which it resembles in structural details. 



Usually not uncommon in north and central Europe, occurring in 

 grassy places throughout Sweden from early June to August ; it is re- 

 corded from Holland in June and Belgium in August; Gaulle tells us 

 it has been raised from Alucita galactodactyla in France. A common 

 species in Norfolk during Jul)- and August, bred from Peronea maccana 

 (Bridg.); and in Devon from Vanessa alalanla through Microgaster sub- 

 complcliis (Bignell, List <-/ Entom. 1882, p. 14.1). It is certainly uncommon 

 in Suffolk, where I have only found it in Tuddenham Fen in June, 1910, 

 and on flowers of Hn-aclcum sphondvlium at Hadleigh at the end of July, 

 1902; I possess half-a-dozen from Shere (Capron), females from Pains- 

 wick in Gloucestershire (Watkins) and on Myrka gale at Matley Bog in 

 the New Forest early in July, 1909. Francis Walker first took it in Eng- 

 land andHalida) found it in woods from June to August, both in Ireland 

 and the Hebrides. Lyle has bred it liyperparasitically from Torfiix 

 ribeaita tlirough l^hylodi'aeUis polyzonias in the New Forest. 



15. dimidiatus, Holnigr. 



Mesochorus dimidiatus, Holmgr. Sv. Ak. Handl. 1858, p. 118, <? ; Brisch. 

 Schr. Nat. Ges. Danz. 1880, p. 180; Thorns. Ann. Soc. Ent. France, 1885. 

 p. 340, c? ? . 



A pale flavous species with the thora.K discally, abdomen basally, stigma 

 and a basal hind tibial dot, black. Head transverse and testaceous with 

 a broad frontal vitta, mandibular teeth and a transverse occipital mark 

 black ; cheeks el-ongate and buccate ; face broader than long and man- 

 dibles somewhat stout with teeth of equal length. Antennae slender, 

 infuscate and as long as body. Thorax coarctate and little longer than 

 high, finely and diffusely punctate ; testaceous or in $ paler, and discally 

 black, rarely rufescent-marked ; upper metanotal areae complete, with 

 areola somewhat broad. Abdomen hardly longer than head and thorax, 

 testaceous with first segment basally ferrugineous, the second and base of 

 third black and in 9 subquadrate, in S subelongate ; terebra short and 

 fiavous. Legs testaceous, with trochanters paler; hind tarsi stout and 

 the claws obviously pectinate ; hind tibiae nigrescent only at extreme 

 base. Wings hyaline with radial nervure apically straight, basal nervurc 

 continuous, stigma piceous, tegulae whitish and areolet of normal size, 

 emitting recurrent nervure from its centre. Length, 7-9 mm. 



This and the four fcjllowing species form a small group having the 

 face of both sexes pale and the anus, at least in V . testaceous and never 

 entirely black. 



Not a conmion species in northern and central Europe ; it was des- 

 cribed from south Lapland in August and is found in Holland in July, in 

 Belgium during April and June, as well as in France; though nowhere 

 yet bred. It has not hitherto been recognised as British, but I possess a 

 single beautiful pair in Dr. Capron's collection from the vicinity of Shere 

 in Surrey, doubtless constituting part of the thirteen species of this genus 

 said by him (Entom. 1880, p. 89) to have been there captured during 

 1879; and I have seen a female discovered in June, 1902, by Atmore about 

 King's Lynn in Norfolk. ^V 



