Pezomachus?^ BRITISH ICHNEUMONS. I95 



second ; fifth only slightly longer than broad. Mesonotum transverse and 

 decidedly shorter than metathorax, about as long as metanotuni ; petiolar 

 area only slightly oblique, its basal costa weak, often wanting centrally, 

 with apophyses small ; acetabula occupying nearly whole of mesosternum. 

 Abdomen moderately punctured and pubescent to the apex, not dull ; 

 spiracles on the basal segment more or less projecting, on the second not 

 far from its margins ; terebra as long as, or slightly shorter than, the basal 

 segment. Legs stout, with the front tibiae inflated ; front coxae produced 

 nearly to the base of the intermediate. 



Head black, with the palpi dull flavous. Antennae with the four or five 

 basal joints red, thence piceous. Thorax and abdomen red, latter with the 

 apical half from the fifth or fourth segment suddenly black. Legs pale 

 red, with the posterior femora and tibiae apically black. 



$. Apterous. Flagellum with basal joint longer than second; fifth 

 nearly twice longer than broad. Meso- and meta-thorax of about equal 

 length, latter with its transverse costa distinct at the sides only. Scutellum 

 more or less distinctly developed. Abdomen somewhat diffusely punctate 

 and pubescent ; basal segment with prominent spiracles, the petiole very 

 little explanate, the post-petiole a little broader and with sub- parallel sides. 



Head black, with the palpi flavous and mandibles apically piceous. 

 Antennae with the three basal joints clear red, the rest gradually darker to 

 the piceous apex. Thorax pale red, with the metapleurae darker. Abdo- 

 men with the three basal segments pale red and the remainder black ; 

 the first and third sometimes infuscate. Legs red ; hind femora mostly 

 and their tibiae apically piceous. Wings usually entirely wanting, though 

 sometimes fully developed. Length, \\-2\ lines. 



The $ is very like that of P. agi/is but differs in having the acetabula 

 scarcely covering more than half the mesosternum, and the three basal 

 segments more or less red. The $ differs from P. corrnptor in the shorter 

 terebra, transverse metanotum, dark anus and legs. I have considered 

 all the British mentions of P. xylochophilus as referring to this species ; 

 " P. acararum, Fab.," is only recorded by Dale, as abundant at Glanvilles 

 Wootton ; P. acarorum, Grav., is now considered distinct and does not 

 appear to be British. 



Bridgman professes to have first recorded the typical form of P. hortensis 

 from Britain, on Professor Thomson's authority (Trans. Ent. Soc. 1886, 

 p. 341), having taken a single male at Brundall, though he does not tell us 

 wherein it differs from that given as synonymous with Ilemimachus avidus 

 in Marshall's 1872 Catalogue and, indeed, it was distinctly (though not 

 very reliably) given as British by Desvignes in 1S56. 



P. avidus^ Forst., is recorded from Heigham osier carr, near Norwich, 

 by Bridgman, as a species distinct from P. /lorfensis, (Irav. (Trans. Norf. 

 Soc. 1893, J). 617) ; Marshall took several males on the banks of a reedy 

 pond in Leicestershire, of which one, most positively identical, was winged 

 (Fnt. Ann. 1874, p. 127); ICIliott has determined a female taken in the 

 Carlisle district by Day, early in October, 1899; lUitler has an example, 

 somewhat doubtfully named hortensis by Ikidgman, taken at Battle in 

 Sussex. It has been bred from Microgaster cocoons by Brischke and 

 from Psyche Cofisfance//a, Perris, by (Jirand. 



P. xylochophi/us was recorded as British by Bignell (Entom. 1882, 

 p. 45), obtained by beating whitethorn at Exminster early in September, 



O 2 



