640 ASILIDiE 



This species v^aries a good deal in size and remarkably in the colour 

 of the bristles on especially the thorax and legs, as mentioned in the 

 previous description. Amongst British species it is liable to be con- 

 founded with ]£utolmus rufiharMs and Machimus rasticus, but the female 

 may be at once distinguished from both of them by the anal circlet of stiff 

 bristles ; the male may be known from Eutolmus rvfiharhis by the absence 

 of any ventral process from the eighth abdominal segment, as well as by 

 the much more extensively white pubescence and bristles, while the male 

 of Machimus rusticus also has a ventral process from the eighth abdominal 

 segment, the base of the tibise obviously (even if only to a small extent) 

 reddish, and the scutellar bristles more numerous. P. aJlicejJS is also 

 altogether a lighter grey fly with the face and especially the face-beard 

 and the frons more whitish than in the others, while the fine pubescence 

 beneath the front tibire is comparatively short and slight and consequently 

 inconspicuous. The very closely allied P. elutvs from the Mediterranean 

 region may be a distinct species, as is noted in the synonymical note below. 



P. aJhiceps is an abundant species on sandy coasts, and 1 have 

 numerous records from Cornwall, North Devon, Dorset, and Hampshire 

 (Christchurch) to Aberlady in Haddington, and Irvine Moor in Ayrshire ; 

 Mr C. Morley states that it is very common on coast sands at Lowestoft 

 Denes and Felixstowe in August, and it is noteworthy that while I 

 cavight immature Pctmijonerus cicrmanims at Barmouth on June 10 and 11, 

 1887, and did not then find P. alhiceps at all, on July 20 and 21, 1888, I 

 found P. alhiccps in abundance but no P. c/ermanicvs. Colonel Yerbury 

 found it common at Waterville and Dooks (Glenbeigh) in Ireland on the 

 sand-hills, and I had an old record from South Tyrone. I believe it also 

 occurs inland on sand-hills and such-like localities. My records extend 

 from June 28 to September 18, and on the latter date in 1907 Colonel 

 Yerbury took a female at Aldeburgh which was feeding upon a female 

 PlatycTiirus fidviventris. It is known to occur over Middle and Northern 

 Europe, but such localities as Portugal and Japan require testing as 

 against P. elutiis. Specimens taken by the late Frederick Smith in North 

 Devon were preying upon Grasshoppers, while Colonel Yerbury records 

 that "A female taken at Dooks was preying on a Lucilia, but at 

 " Waterville the usual quarry was Orygma luduosum, though now and 

 " again an Anthomyid was taken. On more than one occasion instances of 

 " cannibalism were met with, and one (at any rate) of these was that of a 

 " female preying on a female." 



Synonymy. — It is very probable that Moses Harris' Asihis delector (1782) is this 

 species, but his description and figure are far too vague for positive identification. 

 Stephens considered Harris' species (which he incorrectly called As. delecta) to be 

 probably the same as A. cristatus Meig., by which he undoubtedly meant Dysmachiis 

 trUjonus, but Harris' species would be far too large for that as he says " nine lines." 

 1\ eiutus Loew has the face-beard all white (in a female from Kowarz's collection) or 

 with perhaps one black hair (two females from Bigot's collection), the frontal and 

 ocellar hairs all white ex(!ept a few small black hairs close to the upper eye-angles ; 

 the thorax lighter grey than in P. alhiceps with the side-stripes less separated from 

 the middle stripe, and with the tiny bristles conspicuously white all over the disc 

 even to the front part ; wings whiter, with the veins (in Bigot's specimens but 

 hardly in Kowarz's) to a large extent yellowish ; S(iuam£e clearer yellow ; hal teres 

 clearer orange ; a male from Sicily which stood in Bigot's collection under P. albiceps 

 is shorter and whiter, and has a more distinct dark dorsal stripe on the abdomen 

 with far more numerous tiny black bristles on it. Pandelle (Rev. d'Entom., xxiv., 



