202 [February, 



H. aprica, Hal. 



This fine species is the largest and most highly developed in the genus. The 



middle and the posterior legs have the femora 

 and tibia? of a bright reddish-yellow colour in 

 both sexes. The front pair have the femora 

 and tibiae dusky in the males. The females 

 have the coxae yellow, and also the anterior 

 femoi'a and tibiae in many specimens ; but 

 sometimes they are darkened, as in the males. The abdomen is sometimes grey in 

 both sexes, and sometimes partly yellow and translucent. It is generally distributed 

 but not common. The females are moi*e frequently seen than the males. 



H. fttscula, Fall. 



Of this rather peculiar and well-marked species, which has the tibiae reddish or 

 piceous, I have only seen a single female, which I captured near Edinburgh in 

 August, 1875. The best description is given by Zetterstedt, in the Diptera of 

 Scandinavia. He notices the male in the 4th vol., p. 1686, and, in vol. 8, p. 3310, 

 gives a correct account of the female, which has the frontal space comparatively 

 narrow. He says that both sexes of this fly were found by Staeger in the nest of a 

 humble bee. The specimen which I found was covered by a number of Acari, similar 

 to those which infest bees and beetles, so perhaps it had been in a bees' nest. 



H. pallitibi^:, Eond. 

 This small species has the knees and tibiae pale, in both sexes. It appears to 

 be rare ; I have one pair ( J & ? ) captured in the neighbourhood of Bradford. 



H. scalaeis, Fab. 



This common species, characterized by the projecting tubercle on the inner sides 

 of the middle tibiae of the males, sometimes has the anterior tibiae yellow at their 

 bases, when it forms the A. manicata of Macquart (not of Meigen). I have a variety 

 in which the second and third abdominal segments are yellow and translucent at 

 their sides, as in H. canicularis ; this is probably the same as the A. subpellucens, 

 Zett. 



H. CANICTTLAEIS, Lin. 



This, though the best known and the most common species, and the one which 

 is generally considered as the type of the genus, really possesses fewer characteristic 

 features than most of the others ; the eyes being proportionately smaller, covering 

 less of the cheeks, and the middle tibiae being simple, without any tubercle or marked 

 thickening. 



H. incisurata, Zett. 

 This species bears a very close general resemblance to H. scalaris, in size, shape 

 and design ; it differs, however, by having the thorax grey, not black, marked by 

 two or more less distinct stripes, and by the intermediate tibiae being simple, as in 

 H. canicularis. Kondani does not seem to have known this species, for he confuses 

 it with H. lepida, Wdm., which appears to me to be synonymous with H. mutica, 



