552 THEREVID^ 



Yerbury also took several specimens at Porthcawl in G-lamorgan in 1903 

 and 1906, and these are the only other British specimens I have seen. 

 The dates range from June 10 to July 8. 



Synonymy. — As I liave said above I believe tliat all the old British records (with 

 the possible exception of Stephens') refer to other species and mainly to T. nohilitata. 

 I cannot doubt the correctness of my own determination even though Loew stated 

 that the " sehr intensive gelbe Fiirbung und, ausser den gewcihnlichen schwarzen 

 " Borsten, keine Beimischung schwarzer Harchen." Walker's description applies 

 fairly well to the female, but his statements of ^'' hind borders of the third and folloiv- 

 " ing segments black, shining ; underside grey, ferruginous and shining at the tip ; " 

 are not very applicable. It is also remarkable that I have never seen a specimen 

 of T. fulva. in any old British collection. In ray notes on the synonymy of the 

 genera of Therevidm (page 544) I have called attention to the possibility of the 

 genus Exapata having been founded upon a distorted specimen of this or some 

 closely allied species. 



2. T, arcuata Loew. Thorax dark brown with two narrow pale stripes. 

 Pubescence mainly rufous orange, but the abdomen with consjDicuous jet 

 black bands; jowls without a clump of black hairs. Abdomen rather 

 narrowly conical. Praesutural bristles often two pairs. Tarsi ferruginous 

 only at the extreme base. Wings with a very faintly clouded arc above 

 the discal cell; fourth posterior cell often just open. 



Var. inornata Verrall. Pubescence grey or greyish yellow, with 

 indistinct black bands on the abdomen. Tarsi considerably ferruginous. 



A rather elongate conical species which is distinguished in 

 its typical form by its beautiful rufous orange pubescence 

 which with the jet black bands across the abdomen give it 

 a very striking appearance, though the form inornata bears 

 a strong resemblance to T. nohilitata. 



$. Face and frons covered with greyish tawny dust, which however has a 

 blackish tinge on the upper part of the frons ; frons bearing long black 

 pubescence which spreads out like a fan at the sides and extends down fully 

 two-thirds of the sides of the face, but then grows scarcer until it is reduced 

 to a single line of hairs or sometimes dies out on the lower sixth of the 

 face ; all the middle part of the face bearing dense bright foxy tawny 

 pubescence (in which one or two black hairs may be detected), but the black 

 hairs on the sides just below the antennae may stray out for a short distance 

 and on the other hand the foxy pubescence may extend all round the antennae 

 and occupy all the front part of the frons (unless obscurely just about the 

 middle) ; a shimmering whitish margin encircles the lower half of the eyes ; 

 the foxy pubescence clothes all the lower part of the head (amalgamating 

 with the similar dense pubescence on the front coxse) but a thin line of 

 black hairs runs under the lowest angle of the eyes, and the black hairs 

 extend a short distance up the back of the head ; back of the head otherwise 

 clothed with foxy pubescence which however becomes rather darker on 

 the upper jjart, and with the usual overhanging long black postocular 

 ciliation on the upper part which extends to the more dense black hairs on 

 the vertex, while out on the back of the head quite away from the eyes are 

 about half a dozen black bristles which are sometimes difficult to detect 

 amidst the dense foxy pubescence ; vertex covered with brownish dust. 

 Eyes touching or at least approximated for a space which is rather longer 

 than the vertical triangle ; when seen in profile the eyes are deeper than 

 usual in proportion to tiieir length and when seen from above seem to be 

 shorter than usual ; facets almost imperceptibly diminishing from the upper 



