1898.] 39 



Whether the species is Meigen's Tacliina erratica at all seems to 

 me, so far as it is possible to judge from the single $ at my disposal, 

 also doubtful. Meigen [describes the abdominal segments, after the 

 first, as " ash-grey, each with two blackish-brown, triangular, shim- 

 mering spots, which are in contact with the lateral margin." He thus 

 says nothing about a "central dorsal stripe," as described by Meade, 

 while the triangular spots on the second and third segments of the 

 abdomen are a long way from the lateral margins. Meade and Meigen 

 both speak of four black stripes on the thorax, but it is perhaps as 

 well to mention that in the Painswick ? the four thoracic stripes are 

 prse-sutural ; behind the suture there are but three. Finally, it may 

 be observed that T. erratica, Mg., is not included by Brauer and von 

 Bergenstamm in their list of 1520 species of Muscidce examined by 

 them (Denkschr. Math.-Naturw., CI. K. Akad. Wiss. Wien, Bd. Iviii, 

 1891, pp. 421—443). 



XrSTA CANA, Mg. 



This species, described by Meigen under Fhasia, but placed under Xysta by 

 Schiner, who is followed by Brauer and von Bergenstamm, was introduced as British 

 by Mr. C. Morley (Ent. Mo. Mag., ser. 2, vol. vii, 1896, p. 212), on the authority of 

 Mr. Meade, whose identification was based upon a couple of specimens swept by 

 Mr. Morley out of grass at Ipswich : one in May, 1894, and the other on May 23rd, 

 1896. Mr. Morley having recently been good enough to allow me to examine these 

 specimens, I found that they agree in all respects with a single specimen in the 

 Museum collection from Felden, Herts, May 14th, 1894 (A. Piffard), which I had 

 previously identified provisionally as \Phasia Rothi, Ztt. (Dipt. Scand., xiii, 1859, 

 pp. 6170, 6171). The three specimens agree fairly well with the description of cana, 

 except that in Meigen's description there is no mention of macrochsetse on the 

 abdomen, whereas in these specimens the posterior margins of the second, third, and 

 fourth abdominal segments are sparsely fringed with such setse. According to the 

 definition given by Schiner, abdominal macrochsetse are absent in all genera {Xysta, 

 Syntomog aster, Phasia, Ananta, and Alophora) included by him under " PhasincB ;" 

 while with regard to the abdomen of Xysta he expressly states (Faana Austriaca, 

 Diptera, i, p. 407) that : " symmetrically arranged large bristles are nowhere found, 

 even when the hairy coat is pretty thick." It is, therefore, evident that if these 

 specimens really belong to cana, the species is as much out of place under Xysta as 

 it would be if allowed to remain under Phasia. Meigen, however, as already stated, 

 says nothing about macrochsetse in his original description of Phasia cana, whereas 

 Zetterstedt (loc. cit., p. 6171) describes the abdomen of Phasia Eothi, as : " margine 

 apicali segmentorum 3 & 4 parce setulosum " (the macrochsetse on the posterior 

 margin of the second segment are very inconspicuous, being much smaller than the 

 others). For this reason it seems better to designate the species, for the present at 

 any rate, by Zetterstedt's name, instead of by Meigen's, which, if eventually found 

 to apply, would have priority by thirty-five years. In the three specimens that I 

 have examined the fourth longitudinal vein is bent at_an obtuse angle, and the first 



