1. PACHYGASTER 69 



pini is also a synonym, as Mik has already observed, and I can to a large extent 

 confirm this from three specimens in Bigot's collection which he probably obtained 

 from PerriSj and which, thongh in very bad condition, I consider only P. viinutissima. 



2. P. atra Meigen. Wings conspicuously blackened on the basal half. 

 Antennre black in the male, orange in the female. Back of the liead 

 considerably inflated. 



Easily known by the diagnostic characters, though alhed to 

 P. tarsalis (figs. 83, 90). 



S. Head when viewed in profile longer than deep, and when viewed from m. 

 front more than one and a half times broader than deej) (fig. 92). Face and 

 frons when viewed from in front well below the middle of the head and forming 

 a small black triangle, but as the head is so much flattened the face is fairly 

 large when seen from beneath ; the face bears moderate blackish pubescence, 

 ancl in cei-tain lights there is a very narrow pale eyemargin which bears very 

 short pale pubescence ; the flattened lower part of the head causes the jowls 

 to 1)6 shallow, but the lower part of the l)ack of the head is very considerably 

 inflated and bears inconspicuous though dense short blackish pubescence, 



Yui.^l.—Pachygastcr atra i. x 33. Fig. 9S.—Fachygas<cr atra S- x 33. 



while the upper part of the back of the head is shining black, and is 

 inflated and bearing very short dense black postocular pubescence (fig. 93) ; 

 vertex long, narrow, and pointed, extending considerably more than half way 

 from the occiput to the antennae, and in fact leaving the eyes touching for 

 about only four facets ; ocellar triangle with some very tiny inconspicuous 

 lilackish pul )escence. Eyes irregularly circular when viewed sideways, not abso- 

 lutely bare but with very slight inconspicuous short hairs ; facets witliout any 

 distinct difference in size or colour in dry specimens. Antennae dull blackish; 

 two basal joints with some black bristles beneath and at their tips ; arista long 

 and thin, in some lights ahnost whitish, but the very minute dense pubescence 

 makes it appear a little thickened except at the tip. 



Thorax shining black, but dulled by the very dense coarse ijunctuation 

 and the very dense short blackish pubescence ; the pubescence is however 

 very much longer, more erect, and denser than in P. Leachii, and in certain 

 lights is slightly greyish ; pleura? more bare than the disc of the thorax and 

 more shining because less punctate, especially on all the impunctate brilliantly 

 polished middle part of tlie mesopleura?. Scutellum resembling the hinder 

 })art of the thorax in colour and pubescence. 



Abdomen shining black, but dulled by the very dense punctuation, and 

 every puncture bears a tiny blackish grey bristle ; about the sides of the 

 base there are some longer finer almost black hairs. Belly shining black, 

 with short depressed scattered pale grey pubescence. Genitalia exserted 

 from about the middle sixth of the last abdominal segment, dull orange. 



Legs rather pale yellow even to the last joint of the tarsi, but the femora 

 all black except at the extreme tip ; tibial (especially the hind pair) with a 

 darkened ring soon after the base ; coxse blackish ; trochanters brownish ; 

 pubescence very slight, but a little exists on all the femora ; claws blackish. 



