THE ENTOMOLOGIST. 253 



the Blephariptera serrata, a little, sluggish, rust-coloured fly, 

 very common on the windows in the early spring ; also the 

 Lonchaea vaginalis, a little, chubby, steel-blue coloured one, 

 resembling an Anthomyia in form, which is occasionally met 

 with ; and I may conclude ray list with the genera Borborus 

 and Sphaerocera, several of which are often seen on windows 

 in spring and autumn, especially on those near stabling, as 

 these little flies breed in immense numbers in horse-dung. 



Diptera are among the earliest insects which appear in the 

 spring. If a very mild, bright day should occur, even in the 

 beginning of February, numerous small flies may be seen, 

 which appear to be hatched by the sunshine. The most 

 abundant of these are the little dull-coloured species belong- 

 ing to the family of the Borborides, which, I have already 

 stated, breed in manure : one of the most common of these, 

 the Sphaerocera subsultans, may easily be distinguished by 

 the length and thickness of the hind legs, which enable it to 

 leap as well as fly, whence its trivial name. The common 

 house-fly (Musca domeslica) does not occur in any abundance 

 before the middle of summer, owing to its hybernation during 

 the winter, for only a few individuals escape the effects of the 

 cold, and from these the swarms of the ensuing season are 

 bred. The true house-fly is really a domestic insect: it is 

 seldom found far from houses, and chiefly abounds in large 

 towns and cities; in country houses it is sparingly met with, 

 and its place seems to be supplied by other species. I have 

 often examined the flies in the rooms and on the windows of 

 houses in rural situations, and instead of Musca domestica 

 have found Pollenia rudis, or Stomoxys calcitrans. The 

 latter may at once be known from the true house-fly by its 

 having a horny, geniculated and projecting proboscis, with 

 which it can make a very sharp puncture, and suck the blood 

 of man and animals. The former, which is slightly larger 

 than the domestic fly, has the thorax clothed with yellow 

 downy hairs. 



In the spring before the house-fly begins to breed, its 

 place is chiefly supplied in our rooms by one or two species 

 of Anthomyia, The flies of this family may be distinguished 

 at once from the true Muscida?, by the disposition of the 

 veins or nerves of the wings. In the genus Musca the filth 

 longitudinal vein (sometimes called the pnebrachial) is bent 



