Polysphincla.] BRITISH ICHNEUMONS. .119 



stricted towards the mouth; checks short and not at all buccatc ; clypeus 

 discretcd, convex, apically broadly rounded and usually finely margined 

 thou^di not impressed ; mandibles somewhat narrow and gradually dilated 

 basally, with the lower tooth usually somewhat the shorter ; maxillary 

 j)alpi subelongate with the three apical joints subecjual in length. Antennae 

 short or of normal length, slender, filiform though slightly attenuate api- 

 cally ; scape apically nearly entire or a little excised externally at the apex ; 

 basal flagellar joint somewhat elongate, cylindrical and the apical one 

 conical, sometimes double the length of the })enultimate. Thorax gibbu- 

 lous, longer than high and narrower than the head ; pleurae smooth and 

 nitidulous; epomia distinct; mesonotum ovate with (hstinct apical notauli ; 

 metathorax with the areae complete, obsolete or wanting ; areola some- 

 times finely delineated, petiolar area very small and often entire ; spira- 

 cles circular and minute. Scutellum subquadrate or subtriangular, apically 

 obtuse and a little convex. Abdomen sessile or rarely subsessile, as broad 

 as and twice longer than the thorax, oblong or cvlindrical ; epipleurae 

 subobsolete ; basal segment either subquadrate or a little longer than 

 broad, rarely basally subconstricted, more or less distinctly bicarinate and 

 transversely impressed before the apex with the tubercles near the base, 

 segments two to four or five transversely impressed and tuberculate with 

 the elevations nitidulous, and more or less punctate ; the sixth and seventh 

 of 9 ^vith the venter longitudinally cleft ; terebra normally or shortly 

 exserted, never longer than the abdomen and rarely longer than its half, 

 spicula strongly acuminate with the valvulae pilose. Legs normal or 

 slender, with the femora somewhat stout ; apical joint of the hind tarsi 

 usually dilated, longer and broader than the penultimate, with the claws 

 stout and in 9 basally lobate ; the hind tibiae longer than their femora, 

 with short and subequally long calcaria. Wings normal or ample ; areolet 

 wanting or obsolete, never entire ; radial cell sublanceolate ; nervellus 

 either slightly curved and not intercepted or distinctly bent and emitting 

 a more or less distinct nervure. 



The genus was originally distinguished from Pimpla, which it resembles 

 in all superficial facies, by the lack of the areolet, which in Pimpla pictipes 

 is said to be minute and nearly obsolete. Holmgren found, however, 

 that, although it resembled Pimpla in the abdominal conformation, the 

 terebra was as a rule shorter, and the clypeus, besides being more convex, 

 was not or very rarely deflexed, never impressed though vcxy often mar- 

 gined before its apex. It differs from Schizopyga in its more slender legs 

 and longer terebra ; and from Clisfopyga the 9 is distinct in the cleft 

 hypopygium. Little or no reliance is to be placed upon the extent of 

 rufescent thoracic, nor nigrescent pedal, coloration in this genus. 



The species of this genus appear to be almost* or quite exclusively 

 ektoparasites of the Arachnida and several very interesting and economi- 



Mt is mainly in Ratzeburg's " Forstinsektcn " tliat the excejnions occur. He bred a very remark- 

 able number of hymenopterous parasites, but the association was not always as satisfactorily estab- 

 lished as one could wish, and in the case of species first described by him there is the additional 

 danger that he may have not referred them to their correct genus- by no means a simple task in those 

 days (1844-52). I-"or instance, his /'. elet^ans is synonymous with Clistnf>vf;a incitator, l-'ab., and, since 

 it wras bred out of beech logs together with his /'. soror, various Aiwbii and I'tilini, it is not impos- 

 sible that the latter may also be extrageneric His /'. aieularis is probably the i of some Tryphonid, 

 since it was bred in August from three sjiccies of sawfly; from the cocoons of Tnchiocitmpus vimi- 

 nalis, I-all. in May, from Croesus ieptcntrioualh, Linn., and rontania sd/jVis, Christ. His I'.lathttiata 

 appears, from the figure of the wing (ii. pi. i, fig. ii) to bo a true <? of Ibis genus, but it is said to have 

 been bred from the epidermal bladders of Orchestes quercus (cj. Trans. Ent. Soc. 1907, p. 49). /'. vclata, 

 Htg., was raised by its author from the larvae of Geoineti a piniaria (Jahrcsb. 183H, p. 262). Ratze- 

 burg's F. ribesii, bred from I'lcroiius ribcsii by Hrischke, and his /'. lif^nicola, thought to have been 

 parasitic on some Ctrambyx, are still less satisfactorily included in the present genus as insufficiently 

 described or doubtful, by Schmiedeknecht, who makes no mention of the last. Urischke says he has 

 bred /-". carbonata from a sawfly, Nematus vcntricosui, which Hitch suggests is an error. 



