76 STRATIOMYID^ 



certain trees, such as P. orbitalis to Holly (Ilex), P. atra to Elm (Ulmus), 

 P. minutissima to Pine (Pinus), P. tarsahs to Beech (Fagvs), and Poplar 

 (Populus), and P. Leachii to Oak (Quercus). At jjresent we hav^e a record 

 of P. atra from beneath the bark of Pmus sylvestris, but as this record was 

 made by Schilling, who was not a dipterologist, in 1829, when P. minutis- 

 sima was unrecognised, it is easy to imagine that an error might have 

 arisen ; I believe, however, that Dr Sharp has bred P. tarsalis from 

 Beech, Poplar, Elm, and Pine. Carcel's record of P. atra in rotten wood in 

 an Elm (Ulmus) is undoubtedly correct as it was tested by Macquart; P. 

 vmiutissima { — P. inni Perris) has been associated only with Pine {Pinus) ; 

 P. meromelas was bred by Dufour, who was a very imperfect dipterologist, 

 from beneath the bark of an old dead Poplar (Populus), and his species has 

 been hitherto believed to be synonymous with P. orhitalis, but I believe a 

 mistake has been made in this, and that his species is really a synonym of 

 P. tarsalis ; P. Leachii has been bred from a Boletus found in a hollow oak 

 (Quercus), which may well mean that it lived on the detritus from some 

 Coleopterous larv?e which fed on either the Boletus or on the Oak {Quercus), 

 and it has also been bred from old turnij) stems (Brassica Bc(pa) ; P. 

 orhitalis according to Wahlberg " Hab. in liguo Populi cseso," but he does 

 not absolutely say that it was Ired. from Populus, though it may be pre- 

 sumed that it was. Now that so much attention has been drawn to the 

 larvae of this genus, which can apparently be easily reared, while the perfect 

 insects are usually very uncommon, we may hope that further investigations 

 will be made with a view to determining the exact nature of their food. 

 P. orhitalis is known with certainty from Scandinavia, Germany, and 

 France. 



Si/nony7ny. — There can be but little doubt that this is the true /■'. orhitalis of 

 Walilberg (1854), because he says "orbitis infra antennas late argenteis," and he 

 gives amply sufficient distinctive characters as against the four other known 

 European species ; the only point in his description wliich can be demurred to is 

 " nervis pallidis," because the subcostal vein at any rate can scarcely be considered 

 pale on its basal part ; Wahlberg failed to recognise the male, wliich is not to be 

 wondered at, as he naturally would expect it to differ from the female in the usual 

 way. The next comparatively certain synonym is P. arrjentifer of Jaennicke (1866), 

 but either his supposed male must have been only P. tarsalis or his word " unbehaart '" 

 as applied to its eyes must have been a misprint tor "ungenahert " ; such an error on 

 the part of Jaennicke is not improbable because in his description of P. Leachii he 

 gave " hinterscliienen " when he meant "hinterschenkel," but when he went on to 

 describe the male of his P. argentifer as having "die Scliwinger...scliwarzlich...auch 

 der Stiel schwarz," it became certain that his male did not belong to 7\ orhitalis. 

 Loew (1870) disposed of P. argentifer as an absolute synonym of the species which 

 he called P. meromelas, and I think he was quite right inasmuch as I think Loew 

 made just the same mistake as Jaennicke about his male, so that his (single) male 

 was also only 1\ tarsalis; in support of this contention it is quite certain that 

 Loew if he had known the true male of P. orUtalis could not have failed to notice 

 the broad frons, and, as I siiall say under my remarks about P. meromelas of Dufour, 

 the bred specimens of P. tarsalis, or perhaps I sliould say the innnature specimens, 

 show very little darkening on the basal half of the wing. P. meromelas of Leon 

 Dufour (1841) is in my opinion impossible to identify now either liy description or 

 by types ; the description is as follows : 



"Ater, pedibus pallis, femoribus nigris ; alis immaculatis nervis a basi ad 

 " medium atris antennis I'ufo-fuscis." 



"Long. 112 lin. — Hab. in populetis Galliaa meridionali-occidentalis. 



" Cette espece, dont les caracteres sont constans, a la taille et la i)hysionomie du 

 " P. pallipennis, qui est commun sur les feuilles de nos noisetiers, mais elle en differe 

 " par la couleur noire des cuisses et des nervures de la moitie posterieure des ailes : 



