THE ENTOMOLOGIST. 897 



Isosoma luteicolUs. — Mas. Nigra; caput et thorax sub- 

 tilissime punctata; caput prothorace multo latius; antennae 

 filiformes, basi luteae; prothorax luteus ; petiolus longis- 

 simus ; abdomen fere lineare ; pedes lutescentes, femoribus 

 tibiisque nonnunquam ex parte nigricantibus ; alae sub- 

 cineresB, nigricante venosoB. 



Male. Black. Head and thorax shining, very finely 

 punctured. Head much broader than the prothorax. An- 

 tennas filiform, rather shorter than the body ; first and second 

 joints luteous. Prothorax luteous. Metathorax well deve- 

 loped. Petiole very long. Abdomen nearly linear, together 

 with the petiole not longer than the thorax. Legs hitescent ; 

 femora and tibiae occasionally blackish, except at each end. 

 Wings slightly cinereous ; veins blackish ; humerus longer 

 than the ulna. Length of the body I5- line. 



It can hardly be compared with I. flavicollis and with 

 L fulvicollis, as no male of these two species has yet been 

 discovered in England ; the longer petiole and the darker 

 wing-veins indicate that it is specifically different from both 

 of them. 



Isosoma insolila, — Foem. Nigra; caput et thorax sub- 

 tiliter punctata; caput prothorace paullo latius; antennae 

 subclavata?, thorace multo breviores ; prothorax immaculatus ; 

 petiolus longiusculus; abdomen postice sublatescens, thorace 

 multo brevius ; al^ diaphana:, nigricante venosae. Mas. ? 

 AntennaR filiformes ; abdomen longi-fusiforme. 



Female. Black, slender, shining. Head and thorax finely 

 punctured. Head a little broader than the prothorax, which 

 is moderately developed, and has no trace of the two pale 

 spots which are very generally characteristic of this genus. 

 Antenna3 subclavate, wholly black, much shorter than the 

 thorax ; club fusiform, more than twice as long as the 

 preceding joint. Metathorax well developed. Petiole rather 

 long. Abdomen slightly increasing in breadth from the base 

 to near the tip, very much shorter than the thorax. Legs 

 wholly black. Wings pellucid; veins blackish; humerus 

 much longer than the ulna; stigma very small. Length of 

 the body 1 — 1^ line. Male ? Antennae filiform, about as 

 long as the thorax. Abdomen elongate-fusiform, longer than 

 that of the female. Most allied to L brevis. 



Systole albipeunis, a native of the South of England, also 



