Anthomyicl genera Hammomyia and Hylephila. 323 



and the ocellar triangle, in which space 1-3 pairs of very much 

 smaller bristles may sometimes be found. A few upcurved bristles 

 near the oral margin below the cheeks with some others pointing 

 forwards. Palpi brownish, with few and weak bristles as in buccata. 

 Thorax dull grey, slightly darker on disc and lighter on humeri, 

 notopleural dej)ression and pleurae, and with an ill-defined brownish 

 central stripe, and brownish patches at the base of some of the 

 larger bristles, at sides about the suture, and at end of scutellum. 

 As in unisiriala there is no strong posthumeral bristle; pre-alar 

 bi'istle short but distinct. Abdomen light grey, more or less con- 

 spicuously tessellated, and with a central brown stripe, which when 

 viewed from behind is not sharply defined but varies according to 

 the point of view, and when viewed from the side may completely 

 disappear. Hind-marginal bristles very long and strong. Chae- 

 totaxy of legs very much as in personata, but the posteiovential 

 bristles to hind femora are shorter and finer; the hind tibiae are 

 more strongly bristled and bear behind a distinct row of 10-12 

 short bristles. Wings with yellowish veins ; the postical cross- vein 

 somewhat oblique and distinctly smuous. 



$. Distinguished at once from any other British species by the 

 wide frons (about J the width of head). It much resembles the 

 female of albescens and sociata, but the arista is practically bare 

 and there are no indications of any true orbital bristles. Frontalia 

 of almost equal width throughout ; frontal orbits rather wider than 

 frontalia except right above at each side of ocellar triangle. Thorax 

 a little more yellowish-grey than in the male, otherwise very similar. 

 Abdomen the same colour as the thorax, with neither the tessella- 

 tions nor the central stripe very distinct; hind-margmal bristles 

 not very strong, strongest on fourth segment, those on fifth seg- 

 ment much weaker. Chaetotaxy of legs very much as in per sonata 

 but all bristles rather weaker, no bristle beneath middle tibiae, 

 and bristles of anteroventral row to hind femora most conspicuous 

 towards tip. 



Length 7 mm. (^ ; 5-6 mm. ?. 



H. sjMtisa appears to be ratlier uncommon in Britain. 

 Col. Yerbury caught a male at Llangorse (Brecon) on 

 June 1st, 1899, and Mr. A. H. Hamm a female at Shotover, 

 near Oxford, on June 12tli, 1904, when collecting Aculeate 

 Hymenoptera. There is also a female in the Verrall 

 Collection taken in Hay ling Island in June 1886, and two 

 old males without history. In the Cambridge University 

 Museum there is a male labelled " New Forest, June 1902, 

 M. A. Sharp." The name is new to the British List. 



