134 HYMENOPTERA. 



The genera likely to be found in England may be at once 

 discriminated as follows, but it appears that all except the 

 first are uncommon : — 



i. Antennas 12-jointed, $ $ : Perisemus. 



ii. Antenna? 13-jointed, $ % 



•f Wings with a stigma Goxiozus. 



ff Wings without a stigma. 



* Wings with a ramus marginalis Bethylus. 

 ** Wingswithoutaramus marginalis Ateleopterus. 



I have taken, in the He de Cam argue, near Aries, the 

 sexes of Forster's Isohrachium dichotomum, Verb. pr. 

 Eheinl. 1851, p. 13, pi. i. f, 6, = (^H)omalus nigrieornis. 

 Nees, Mon. ii. 392, $, = {H)omahis fuscicornis, Nees, 

 I. c. ? . This is the insect with which our Perisemus was 

 formerly confounded, but it is much larger, and the $ has 

 13-jointed antennae, &c. The possession of these specimens 

 was a great help towards identifying the English form. To 

 the genus Isohrachium belong Scleroderma mutilloides, 

 Costa, and Epyris pulchellus, Lucas. 



The following new species belongs to the Ceraphronides, 

 and if the genera were less minutely defined, it shoidd be 

 placed under Ceraphron, sensu str. But, as this cannot be 

 done without disregarding some leading characters of that 

 genus, I am obliged to form a new one. 



Triogmus, n. g. 



Antennce $ W-articulatcB. Mesothorax lineis 3 longi- 

 tudinalibus impressus. Metathorax hrevissimus, spina 

 sub scutello, spimdisque 2 lateralibus armatus. Alarum 

 stigma lineare, suhnullum ; radius elongalus^ curvatus. 

 Abdomen sessile, segmento 2do maximo, pctiolum abscon- 



