214 BRITISH ICHNEUMONS. [ Exenterus 


flavescent apically. Legs red with the anterior coxae and trochanters 
flavous; hind coxae and marks on their trochanters black. Length, 
4—5 mm. 
Not noticed in Britain till 1881 (Trans. Ent. Soc. 1882, p. 160), though 
one of our commonest marsh species. Both sexes at Brundall, near Nor- 
wich, in autumn (Bridgman); Bickleigh on 30th August (Bignell); Nun- 
ton in Wilts (Marshall coll.). I have swept it in the most boggy places 
at Barton Mills in the middle of June, and towards the end of September 
in both Tuddenham Fen, and Pakenham Fen, in Suffolk. 
TRICAMPTUS, Forster. 
Forst. Verh. pr. Rhein]. 1868, p. 194; Thoms. O. E. ix. 886. 
This genus is unmistakable in the very curious sinuation of the basal 
segment and the strong infumescence of the anterior half only of the 
front wings. 
1. apiarius, Grav. 
Tryphon apiarius, Gr. I. E. ii. 196; Ste. Ill. M. vii. 242, ¢ ?. Exenterus 
apiarius, Schidd Guér. Mag. Zool. 1839, p. 12, nota; Holmgr. Sv. Ak. Handl. 
1855, p. 228; Voll. Pinac. pl. xlii, fig.7, ¢ ?. Cteniscus apiarius, Brisch. Schr. 
Nat. Ges. Danz. 1878, p.104, ¢. Tricamptus apiarius, Thoms. O. E. ix. 
886, 5 ?. 
Head with the mouth, internal orbits and a large facial mark flavous. 
Antennae nigrescent, the three basal joints black and the following fer- 
rugineous beneath. Thorax immaculate black with very distinct 

metanotal areae. Scutellum at least apically, and postscutellum, flavous. 
Abdomen with all the segments flavous-margined, the first occasionally 
immaculate or only apically flavous dotted. Legs normal, the anterior 
flavous beneath, with trochanters entirely infuscate and the tibiae exter- 
nally, especially towards their apices, fuscescent ; hind legs with the tibiae 
