42 Rev. T. A, Marshall's Monograph of 



their base, sutures and anal extremity pale. Autennte 18-16-jointed, 

 almost 3.8 long as the body, slender, pale yellow at the base, the 

 liagellum forruj^inous, sometimes rather obscure. Mesonotum either 

 feiTuginous or bhickish, the usual furrows often yellow, feebly traced ; 

 scutelhim testaceous ; metathorax rufesceut, areated by elevated 

 lines darker than the ground colour. Wings hyaline ; squamuloe 

 and radicles jmle yellow ; nervures brownish or testaceous ; stigma 

 pale yellow, almost colourless ; cubital nervure attaining the end of 

 the 1st cubital areolet. Legs pale yellow. Abdomen elongate, com- 

 pressed and carinated towards the extremity ; 1st segment sublinear, 

 three times as long as broad, infuscated in the middle, its tubercles 

 situated beyond the middle, scarcely perceptible ; 2nd and 3rd seg- 

 ments infuscated above, yellow on their ventral surface ; 4th and 5th 

 with only a small brownish spot on the disc, the rest clear yellow. 

 Valves of the terebra black. ^ unknown. Length, li ; exp. 2i 

 lines. 



Tliis species may easily be mistaken for A. rosi& (sp. 

 10), which is occasionally found on nettles, or even for 

 A. lonicerx (sp. 11), but these can be distinguished by 

 their black antennae, shorter and stouter than those of 

 nrticx. It is a not very abundant parasite of Siphonopliora 

 urticx, Kalt., the puceron of Urtica dioica, but which 

 infests also Geranium rohertiannm, Malva sylvestris, and 

 Chelidonium majns. The males have hitherto escaped 

 observation, though I bred the species with special 

 reference to them. Some of the Aphides which were 

 watched for this purpose produced tlie common hyper- 

 parasite Lygoccrus carpentcri, Curt. ; others, the apterous 

 Cynipid, AUotria cursor, Hartig. From one of them 

 Bignell obtained Agonioncnrus hasalis, Westw., a rare and 

 little known Chalcid, of which I have given a figure, I 

 believe for the first time. With urticm commences the 

 long series of normal Aphidii. 



9. Aphidius gregarius, Marshall. 



A. gregarius, Marsh., E.M.M., vol. ix. 1872-73, p. 123; 

 Spp. des Hym. d' Eur. et d' Alg. Bracon., vol. ii. 

 p. 569, ^ ? ; pi. xix, f 1. ? . 



5 Abdomen after the 1st segment entirely testaceous. Rufotes- 

 taceous ; head black ; mesonotum and metathorax red, more or less 

 brownish or obscure. Head transverse, wider than the thorax ; oral 

 parts testaceous. Antenna) shorter than the body, blackish, 20- 



