Polyblastus | BRITISH ICHNEUMONS. 289 

discreted with its lateral foveae not tomentose, and the apical margin 
both ciliate and slightly reflexed; mandibles short and broad with the 
teeth subequal in length. Antennae not short, about as long as body; of 
¢ not centrally dilated. Thorax gibbous; metathorax short and semi- 
globose with the discal areae entire, obsolete or wanting. Abdomen not 
petiolate, hardly longer than head and thorax; first segment usually a 
little contracted gradually towards its base, with distinct discal carinae; 
terebra subexserted, stout and larviferous. Legs slender; hind tarsi not 
incrassate; claws basally strongly, apically much more weakly, pectinate, 
in ¢ occasionally submutic. Wings broad and not long; areolet petiolate 
and nearly always more or less entire. 
The genus Scorpiorus, FGrst., differs from the present in nothing but its 
lack of areolet and has a most improbable right to distinction; Thomson 
uses the name for species of the present genus with complete areolet, and 
relegates to it such as have the abdomen centrally red and the ungual 
pectination unusually weak. Other species of Polyblastus have been 
curiously and quite unwarrantably distributed by Dalla Torre, who 
obviously followed authors and not generic characters in compiling his 
very excellent and generally accurate Catalogus of rgot. 
Fourteen species were placed under the present genus in our 1872 
Catalogue, of which P. zmpressus is now known to belong to the Try- 
phonini, P. haemosternus, Hal., is omitted as insufficiently described, 
Bassus rufiventris was misplaced here, and four more are synonymised. 
To the remaining seven kinds I was enabled to add nine in 1901, of which 
two belong to other genera. This total of fourteen is here increased to 
eighteen species, but even so shadows of no less than seven more are 
before me, recorded in MS. by Marshall; these I have not examined and 
exclude till they may be more satisfactorily placed upon our List. The 
genus has been very little worked and much synonomy is sure to accrue, 
since Holmgren’s material was often scanty. 
The genus is celebrated as the only one in which the females carry 
their extruded eggs or larvae attached to the venter, as was especially 
noted by all the earlier authors to Stephens and Fonscolombe. West- 
wood well sums up what was known upon the subject in 1840 (Introd. 
ii. 146); he says, “Gravenhorst first noticed (Ichn. Eur. ii. 151 ef 222) 
that the females of various species were furnished near the extremity of 
the abdomen on the underside with a variable number of small pear- 
shaped or oviform vesicle-like bodies of a white or straw colour, being 
more obtuse and darker-coloured at the tips, of which he says ‘ova esse 
videntur’. Subsequently Haliday communicated to Curtis specimens of 
the latter insect (P. variztarsus) ‘with a sketch of the larvae, for such they 
are, and not eggs’ (cf. P. cothurnatus, post) ‘in different stages’; and he 
found as many as eighteen of them attached to one insect: ‘at first they 
are all smooth, pear-shaped, and of a shining opaque waxy tint, but in a 
few days they appear different; at this stage its voracious powers develop 
themselves, and I find the oldest generally making a meal of his next 
neighbour, who is soon sucked to the skin. I observed two motions of 
the mouth, one an opening and shutting of the mandibles, the other a 
general dilatation and contraction of the membrane ofthe mouth. Beyond 
this they show little signs of life while attached to the oviduct, but on 
being removed, which is easily done without injuring them, the darker 
ones have a slight jerking motion.’ The observations of De Geer enable 
us to judge of the true nature of these bodies” (?) “respecting which 
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