24 BRITISH ICHNEUMONS [Helictes 



2. mediator, Schiod. 



Megastylus 'mediator, Schiod. Gu^r. Mag. Zool. 1839, Ins. p. 5 e^ Nat. Tids. 

 847. p. 97, ? ; Holmgr. Sv. Ak. Handl. 1855, p. 129, tT . Idioxenus mediator, 

 Forst. Verb. pr. Rheinl. 1871, p. 95, j- ?; Brisch. Schr. Nat. Ges. Danz. 1878, 

 p. 77, <r . Helictes mediator. Thorns. O.E. xii. 1312, s ? . 



Black with the abdomen centrally entirely and the legs rufescent, hind 

 coxae nigrescent towards their base and antennae longer than thorax ; 

 eighth flagellar joint of ^ hardly emarginate. Length, 5-6 mm. 



Very like the preceding species but the 9 antennae are longer with 

 the second flagellar joint at least twice longer than broad, the hind tarsi 

 more slender with the fourth joint very nearly twice longer than broad, 

 and the metanotal areola hardly indicated ; the ^ has the eighth flagellar 

 hardly at all emarginate and the head more strongly constricted posteriorly. 



Schjodte first took the female in Danish woods during October; and it 

 is said to be not uncommon throughout northern and central Europe. It 

 is extremely like the next species and I am not satisfied respecting their 

 distinction, since Thomson does not refer to the latter. The present 

 insect is recorded from Exeter early in September by Bignell, and from 

 Brundall near Norwich in July by Bridgman; Capron records it from 

 Shere in Surrey (Entom. 1880, p. 89) and there are half a dozen in his 

 collection. To me it has occurred only twice, at Matley Bog in the 

 New Forest early in August, iQoi, and by sweeping nettles by a wood 

 at Wherstead, near Ipswich, on 27th October, 1903. 



3. borealis, Holmgr. 



Megastylus borealis, Holmgr. Sv. Ak. Handl. 1855, p. 129, c? ? . Idioxenus 

 borealis, Brisch. Schr. Nat. Ges. Danz. 1878, p. 77, ¥ . Helictes borealis, Schm. 

 Opus. Ichn. 2249, <J ? . 



Schmiedeknecht tells us that this species is similar to H. 7nediafor, but 

 with the head scarcely constricted posteriorly and the hind legs much 

 darker; and diff"ering from both the last species in having the abdomen 

 not centrally red but with only the incisures of the three basal segments 

 dull testaceous; the metathorax of the female is distinctly a little dull 

 with its areae more distinct and that of the male shining, with no areae. 

 Length, 5 mm. 



He also only records it from Lapland and northern Sweden — where 

 Holmgren tells us it occurs in shady woods from August 4th to Septem- 

 ber 1st — though allowing Brischke's Prussian reference to be correct. 

 Possibly our species is not the true M. borealis; it certainly has all the 

 features ascribed to it, 



"In the genus JMegasiyhis I have to add M. borealis, Holmg." to the 

 British fauna, says Capron in his Notes on Hymenoptera about Shere 

 (Entom. 1880, p. 89) ; and Bignell subsequently took it at Bickleigh, 

 Plym Bridge and Oreston in Devon during June, July, August and Sep- 

 tember. I have found it equally common from May 3rd to October loth, 

 though it appears to be a summer rather than an autumn species. Besides 

 the six in Capron's collection referred to above, I have it from Banchory 



