28 Rev. T. A. Marshall's Monograph of 



1. Trioxys audits, Haliday. 



Aphidius {T.) audus, Hal., lib. ciL, 489, ^ $ ; Marsh., 

 lib. cit., p. 550, ^ $ . 



$ Head and thorax black, shining ; abdomen piceous, paler or 

 even yellowish in the middle of the base ; 1st segment fulvo-rufou-. 

 Antenna; 12-jointed. Oral parts rufo-tlavescent ; base of the antennae 

 of the same colour. Wings hyaline, somewhat obscure ; stigma 

 narrower than in most of the species, rufo-llavescent diiring life, 

 afterwards, pale brown, like the nervures. Legs fulvo-rufous ; 

 coxiB of the 4 posterior, middle of their femora and of their tibia*, 

 and tij^s of their tarsi, blackish. First abdominal segment rather 

 stout, having its spiracles between the base and the middle. ^ 

 Antennpc slender, elongate, black, 12-jointed ; fore femora infuscated 

 above, tibise of the same pair infuscated in the middle ; 4 posterior 

 legs darker than those of the female. Length, | ; exp. 2 lines nearly. 



Not uncommon ou willows in England ; taken also in 

 Holland by Van Vollenhoven. 



2. Trioxys brcvicoriii&, Haliday. 



Aphidius (T.) brcvicoi'nis,!!^}., lib. cit., 491, % ; Mar-sh., 

 lib. cit., p. 551, $ . 



9 Black ; abdomen pale brownish, darker at the sides, dull 

 testaceous at the extremity. Antennae 10-jointed, very short, 

 thickened towards the tips : apical joint large, oblong, 3rd pale at the 

 base. Legs piceous, all the knees, as well as the underside of the fore 

 femora and fore tibia?, ferruginous. Spiracles of the first segment 

 indicated by minute denticles, situated near the middle, more or less 

 indistinct. ^ LTnknown. Length, J ; exp. '^ line. 



Found by Haliday ou Umbellifcrx, especially the 

 Angelica syhcstris, but unnoticed since his time. 



3. Trioxys hcraclci, Haliday. 



Aphidius (T.) heracki, Hal., lib. cit., 490, ^ ? . 

 Apihidius obsoletus, Wesm., Nouv. Mem. Ac. Brux. 1835, 



p. 83, $ , pi. i, (wing) ; Ratz., Ichn. d. Forst., ii, 58 ; 



iii, G2, ^ ? , pi. ii, f. 27 (wing). 

 T. hcraclci, iJarsli., lib. cit., p. 552, ^ $. 



$ Black ; face yellowish, abdomen of the same colour, infuscated 

 in the middle. Antenntc ll-jointed, progressively thickened from 



