4G0 CYRTID.E 



pale yellow, long and conspicuous. Pubescence pale yellow and very minute 

 all over, with a slight tendency to a short fringe behind the posterior femora. 

 Wings hyaline with a faint yellowish tinge; veins darkened and rather 



distinctly defined, though the lower 

 -'-^'^sf^'^'^ "•-— I ~^^ oi^es hardly reach the margin ; sub- 



/f^ ^------''^^^I--r''''''^Z--^^^^^ costal vein thickened, darkened, 



/^ ~p^ ^\ y'''^^'\,'-'y^'y'- '" ^iid almost reaching the wing-tip ; 



y^ \/ //^' radial vein obsolete, or almost so, 



<r.. y /.■■■'' though occasionally there are vague 



'^- - indications of it or even a detached 



YiG.i^l.—AcToccra globulus i.\z.x. x 14. piece existing (fig, 267). Thoracal 



squanice very large, obscurely vit- 

 reous, bare (except microscopically) but with short pale yellow fringes and a 

 narrow glistening whitish margin ; alar squamse small, whitish glassy. 

 Halteres clear yellow, knob rather large. 



? . Not unlike the male, but with the usual sexual distinctions. 



Head smaller than in the male. 



Thorax with shorter and greyer pubescence. Scutellum all black, but 

 usually with a brownish tinge which becomes more obvious on the underside. 



Abdomen in mature specimens shining black with a brownish tinge ; 

 second segment with a pair of long narrow well-separated inconspicuously 

 luteous spots on the hindmargin ; third segment with a pair of large obscurely 

 bone-white spots on the hindmargin which unite and form a large spot 

 occupying more than half the depth of the segment but emarginate anteriorly 

 at the middle and shelved off at the sides and not nearly reaching the 

 sidemargins ; fourth segment all obscure bone-white except on the blackish 

 foremargin ; all these markings are however very seldom well defined, and in 

 obscure specimens little can be clearly noted except perhaps very narrow 

 pale hindmarginal seams on the third and fourth segments and the pale sides 

 of the second segment ; the dorsal plate of the fifth segment overlaps con- 

 siderably on to the ventral segments. Ovipositor short and thick, but con- 

 spicuous and ending in a pair of oblong lamellas. 



Legs brownish yellow, with the black tips of the tarsi less determinate 

 and less conspicuous. 



Wings longer, more hyaline, and with the subcostal vein less darkened. 



Length about 4 mm., but variable from 3-5 to 4-5 mm. 



This species has no well-recognised close ally in Europe, as it is almost 

 certain that both A. orhiculus Fabr. and A. tninicla Erichs. are synonyms ; 

 at any rate no good comparative distinctions have been pointed out up to 

 the present. A. Iceta Gerst. from Sardinia is but very little known (only 

 three specimens having been recorded) but apparently has the abdomen 

 entirely orange excej^t for a round black spot on the second segment. 

 A. borealis Zett., of which one specimen of uncertain sex was taken in 

 Lapland in July 1832, is probably only a dark variety of A. globulus ; all the 

 other known European species of Acroccra have the radial vein obvious. 



A. globulus is a species very little known to me in a living state, 

 though I believe it is not uncommon in England and sometimes has 

 occurred in great abundance. Dr D. Sharp has informed me that at 

 Milford in the New Forest it occurred in such numbers at a school outing 

 as to be a nuisance to the children through getting into their eyes, and 

 Schiner states that at Trieste they hovered in the shelter of his cap like 

 Anthomyice and were scarcely to be kept off. I have records from Dorset 

 (Parley Common, Glanville's Wootton) Somerset (Shepton Montague), 

 Hampshire (Lyndhurst, Woolmer Forest, Milford), Surrey (Albury, 

 Wimbledon), Middlesex (Esher, Woking), Sussex (Heathfield), Suffolk 

 (Tuddenham Fen), Lincolnshire (Scotton), Gloucester (Forest of Dean), 



