British BTaconidie. 29" 



the base, which is clear yellow ; last joint incrassated. Pro- 

 thorax yellowish, less frequently brownish. Legs yellowish, 4 

 posterior femora and. tibiae infuscated, except at the base ; hind coxae 

 blackish. First abdominal segment denticulated or crenulate on 

 each side near the middle ; appendages of the ventral valve more 

 strongly curved than in the other species. ^ Almost wholly black ; 

 antennae of the same colour ; fore legs, as well as the trochanters, 

 tibiae, and base of tarsi of the 4 posterior, dull testaceous ; abdomen 

 blackish brown with the l^ase dull yellowish. Length, | ; exp. 1^ lines. 



Parasite of the pucerons of the cow-parsnip, Heracleu'ni 

 sphmidylium ; very common in July, afterwards disap- 

 pearing. Taken in Holland by Van Vollenhoven. 



4. Tno:>'ys aeons, Haliday. 



Aphidius (T.) aceris, Hal., lib. cit., 490, $ . 

 Aphidius cirsii, Curtis, B. E., pi. ccclxxxiii, not of Hali- 

 day, ? . 

 T. aceris, Marsh., lib. cit., p. 552, $ , pi. xviii, f. 4. 



$ Black ; face of the same colour, except the oral parts, which 

 are testaceous ; abdomen brown above, yellow posteriorly, the 1st 

 segment dull testaceous. Antennae 11-jointed, much longer than in 

 any of the following species, progressively thickened from the base ; 

 apical joint large, oblong ; 2nd and 3rd joints dull testaceous. Wings 

 hyaline, pubescent, with a slight dusky tinge ; stigma very pale, 

 almost hyaline ; nervures brown. Legs rufo testaceous ; 4 posterior 

 femora, middle of their tibiae, and tips of their tarsi infuscated ; so 

 also the 4 posterior coxae. Abdomen short, depressed ; tubercles of 

 the 1st segment placed near the base. ^ Unknown. Length, 1 ; 

 exp. 2j lines. 



Curtis in 1S31 described and figured this insect as 

 Aphidius cirsii, a supposed parasite of the aphis of 

 Cirsium arvcnse, or Carduus arvensis. But Haliday, des- 

 cribing in 1833 the same specimen, reared by himself from 

 the puceron of the sycamore, Acer pscndoplatanus, changed 

 the name cirsii, as being incorrect. Taken in Holland by 

 Van Vollenhoven. 



5. Trioxys betuhv, Marshall. 



T. bettilse. Marsh., lib. cit., p. 553, $ . 



$ Black ; head and thorax of that colour, only the oral parts- 

 testaceous ; abdomen black except the 1st segment which is clear 



