Thersilochus] BRITISH ICHNEUMONS 47 



with their base usually piceous or rufescent ; flagellum of $ with fourteen 

 or (ifteen joints, of which the first is as long as second and the apical 

 large, subconical. Thorax dull and somewhat convex ; nietalhorax not 

 rugose, with basal area quadrate and pleurae finely rugose with no sulci. 

 Abdomen immaculate black and laterally compressed, with basal segment 

 rather short, nearly straight and dull ; the second not transverse ; terebra 

 slender and little more than half length of abdomen. Legs testaceous, 

 with coxae and trochanters black ; anterior femora often basally, and the 

 hind ones not infrequently mainly, infuscate. Wings hardly clouded, 

 with stigma infuscate ; apical abscissa of radius straight and nearly twice 

 length of the basal, with short branch ; recurrent nervure emitted before 

 the very short areolar. Length, 3 mm. 



Brischke does not tell us that the male, hitherto known to him alone, 

 was bred along with the female ; if it were, the association would be 

 complete ; he simply remarks {Joe. cit.): Beim J sind die Schenkel 

 gewohnlich heller als beim 9 • The male is not, however, uncommon in 

 England; it differs from the female only in the possession of seventeen 

 flagellar joints and somewhat paler legs. 



Only known from Sweden, France and Prussia, where Brischke bred it 

 from the clavicorn beetle, Mdigethes aetieus, which abounds throughout 

 Britain. Nevertheless, this species needed confirmation as British ; its 

 claim to inclusion in our fauna rested upon a specimen captured by 

 Bridgman during June at Brundall near Norwich (Trans. Norf. Soc. 1894, 

 p. 023), which he queries because the flagellum possessed but thirteen 

 joints; several of mine also have only that number. Not uncommon 

 with us though difficult to determine, except by the number of fiagellar 

 joints. Garde has given me the female from Chatham in May; Tuck, 

 Flatten and I have constantly taken both sexes in equal proportion in 

 Suffolk, always in I\Iay and June, usually b}' sweeping but also on house- 

 windows and whitethorn blossom at Bentley, Monk Soham, Tuddenham 

 Fen, Tostock, Ipswich, Bawdsey and once, on 29th June, 1903, 1 found 

 a female actually in a ground fungus in the Raydon Woods; 1 have also 

 swept it in Roydon Fen near Diss, in Norfolk. 



7. triangularis, Grav. 



Ophion triangulare, Gr. Vergl. Ubers. Zool. Syst. 1807, p. 269. Porizon trian- 

 gularis, Gr. I.E. iii. 781, ? . Thersilochus triangularis, Thorns. O.E. xiii. 1399, 

 <? ? ; (?) Brisch. Schr. Nat. Ges. Danz. 1880, p. 193, rf ? . 



Head subcubical with vertex broad ; frons transversely convex and 

 inflated round ocelli ; temples dull, cheeks elongate and clypeus more or 

 less discreted ; mouth red. Antennae stout with fiagelknn of 9 about 

 20-jointed and of (J about 22-jointed, of which the first is little longer 

 than the quadrate second. Thorax dull with the melathorax rugose ; 

 sternauli distinct, basal area elongate-quadrate and not very distinct. 

 Abdomen black with sides of second segment sometimes rufescent below; 

 basal segment elongate and nearly straight, the second subtransverse, and 

 terebra shorter than first segment. Legs red with the trochanters and 

 dull coxae black; hind femora, except apically, j)iceous or nigrescent. 

 Wings small and hyaline, with stigma infuscate and tegulac testaceous ; 



