104 STRATIOMYID^ 



in size and colour ; the back of the head is all almost equally and considerably- 

 inflated, shining bJack and ahnost impunctate. Eyes bare ; facets all equal 

 and small. Antennae as in the male, but with the third joint rather larger 

 and less blackish or even as orange as the others. 



Thorax with the narrow whitish yellow line from the humeri to the wing- 

 base very gradually widening ; postalar calli hardly brownish ; pubescence 

 greyish white all over, fairly abundant and conspicuous but not so short as in 

 0. analis. 



Abdomen black, with only a triangular yellow spot at the extreme tip ; 

 pubescence all short and greyish white. Belly shining black, and bearing 

 very short whitish pubescence. 



Legs simdar to those of the male, but the blackish ring near the tip of the 

 hind femora sometimes extended on the under side ; tarsi hardly obscured 

 towards the tip. 



Wings with the basal and anterior veins more yellowish, and the outer and 

 posterior veins very faint. Alar squamae smoky with a blackish margin and 

 with the small tuft pale greyish. Halteres yellowish white. 



Length about 4-25 mm. 



This species cannot well be confounded with any other known 

 European one, as 0. analis has the whole of the veins round the discal 

 cell conspicuously blackened so as to form a distinct dark blotch about 

 the middle of the wing, and is also a larger species with a simple cubital 

 vein ; 0. Iconina is more alUed but has a conspicuous yellow spot at the 

 base of the abdomen, and 0. terminata is distinguished from all others by 

 the absence of any side spots on the abdomen. A very large female 

 taken by Dr J. H. Wood at Stoke Wood on July 24, 1897, has a pair of 

 isolated dark orange spots on the frons a little above the antennae and 

 well separated from the silvery side spots ; it also has the legs duller 

 orange. Other females when closely examined show traces of a similar 

 pair of spots, but all the head spots vary in size and range in colour from 

 obscure dark orange to glistening white, while the legs are subject to 

 obscure darkenings on the femora and tibiae. 



0. terminata is very rare in Britain, though 1 do not doubt the Dorset- 

 shire records of Dale and Curtis about seventy years ago. Dr J. H. Wood 

 has taken several specimens since 1897 at Stoke Wood, near Tarrington, 

 and he found it not uncommon in the Monnow Valley on July 3, 1906; 

 Mr C. J. Wainwright took one female at West Malvern on June 8, 1901, 

 in company with 0. analis; all these localities being in Hereforcrshire. 

 Dr Wood's captures ranged from June 20 to July 24. Its distribution is 

 only known to extend from Denmark to Austria. 



Synonym]/. — Walker's 0. tej^minata 'which has "Abdomen ivith a narrotv yelloio 

 " border from the middle to the tip "' cannot possibly refer to this species, but (as 

 Loew surmised) must refer to the female of 0. tenuicornis. In Bigot's collection 

 there were two males and two females labelled 0. terminata, but both the males 

 were 0. flavij^es and one female was 0. analis, though the other female was 

 0. terminata with the third joint of the antennae and the ring on the hind femora 

 only brownish. 



8. O. pardalina Meigen, Cubital vein forked. Scutellum all yellow. 

 Abdomen with united yellow markings round the margin. Legs mainly 

 yellow. 



A medium -sized handsome species. 



