BRITISH ICHNEUMONS. 283 



convex ; pronotum with a basal transverse impression and central tubercle, 

 its epomiae distinct ; mesosternum centrally sub-produced in front,^ its 

 sulci short ; metathorax somewhat produced beyond the coxal insertion. 

 Scutellum strongly convex and protuberant, margined to beyond its centre. 

 Abdomen elongate and narrow, closely punctate ; first segment short, con- 

 vex, post-petiole quadrate; second transversely impressed towards the 

 base, with thyridii at its basal third ; anus acute ; terebra straight, slender, 

 longer than post -petiole. Legs slender ; tarsal claws setosely pectinate. 

 Nervellus post-furcal, intercepted below the middle. 



Table of Species. 



(2). I. Scutellum and thoracic markings not flavous ; 



hind tibiae not basally white I. NIGRICOLLIS, Wesm. 



(i). 2. Scutellum and thoracic markings flavous ; 



hind tibiae basally white 2. THORACICUS, Grav. 



1. nigricollis, Wesm. 



Ischnus nigricollis, Wesm. Nouv. Mem. Ac. Brux. 1844, p. 216, 9 ; Bui. Ac. Brux. 

 1849, p. 43, i ; lib. cit. 1855, p. 432, var. ; Brisch. Schr. Nat. Ges. Danz. 1878, n. 6, 

 p. 60 ; Holmgr. Ichn. Suec. iii. 352 ; Thorns. O. E. xv. 1623 ; Berth. Ann. Soc. Fr. 

 1896, p. 390, i ? . 



Head black, usually with palpi and mandibles pale. Antennae of $ 

 ferrugineous towards the base, of $ tricoloured with the apex sometimes 

 fulvidous or the central band wanting. Thorax black with the pronotum, 

 mesopleurae and sides of the metathorax at apex, castaneous ; notauli 

 distinct ; metanotum rugosely punctate with complete upper areae ; areola 

 elongate, sub- hexagonal ; petiolar area trans-strigose, slightly concave. 

 Scutellum entirely red or black, or more or less black basally ; post- 

 scutellum usually red. Abdomen black with post-petiole, second segment, 

 more or less of third to fifth, red, or with the anterior incisures alone 

 ferrugineous ; anus immaculate ; incisures of second and of the transverse 

 third segment deeply impressed. Legs pale red with the hind tarsi and 

 often their tibiae infuscate towards their apices ; $ with more or less of 

 the coxae and trochanters also often infuscate. Tegulae and stigma fulvous, 

 latter occasionally fuscous ; radix white. Length, 6-7 mm. 



It will be noted from the above description how variable is the colour 

 of this species, the $ of which, moreover, sometimes has a frontal line 

 and the apex of the scutellum whitish ; nevertheless, the mesonotum is 

 invariably black and the hind tibiae are not white-marked. 



This is probably not an uncommon species in Britain, though I have 

 not personally met with it. Bridgman took it at Norwich, and it has 

 several times been bred from Pterophorus galactodactylus by Barrett, 

 Porritt, etc. It occurs on the Continent in France, Germany, Belgium, 

 and Sweden. 



2. thoracicus, Grav. 



hchniis thoracicus, Gr. I. E. i. 647 ; Wesm. Nouv. Mem. Ac. Brux. 1844, p. 215 ; 

 Mem. couron. Ac. Kelg. 1859, p. 82; Ilohngr. Ichn. Suec. iii. 354; Thom.s. O. p]. xv. 

 1624; Berth. Ann. Soc. Fr. 1896, p. 389, i ?. 



Head black, with mouth and frontal orbits stramineous ; $ also with 

 face and usually the cheeks white. Antennae ferrugineous beneath of ? , 



