332 CHARLES T. BRUES. 



The family Phoridae form a very readily recognized group of flies. 

 All are of minute or rather small size and extremely active. They 

 separate themselves sharply from other Diptera by their peculiar 

 antennae and wings; the former consist of apparently a single joint 

 which bears a long three jointed arista ; the wings are provided with 

 two distinct kinds of veins, — a series of very thick ones anteriorly, 

 which reach only half way to the wing tip, and a series of three or 

 four much lighter veins, which pursue a longitudinal course and are 

 distributed over the discal portion of the wing. 



There are known at the present time about one hundred and 

 twenty five species from various parts of the world. Of these about 

 one- half are described from Europe alone, while the greater portion 

 of the remainder belong to the North American Fauna. There is a 

 close connection between the European and American species, many 

 of them being common to both continents. From the large number 

 of species that are found in every locality which is carefully exam- 

 ined, it is probable that the number of living forms is greatly in 

 excess of those at present known, perhaps four or five times as 

 great. Some of the well known species have a very wide distribu- 

 tion. A few of the forms originally described from Europe have 

 Hiice been found in practically all parts of the holarctic region. A 

 wide distribution seems also to be the rule among the few tropical 

 species which I have examined. 



The members of the family are all small and many of them have 

 a more or less hump-backed appearance, due to a great development 

 and arching of the thoracic dorsum. The head is more or less 

 rounded or hemispherical in shape; the compound eyes are well 

 separated above and on the front, while the ocelli, which are absent 

 only in some wingless forms, are placed in a triangle on the vertex. 

 The front, which is from one-half to one fifth the width of the 

 head, is nearly always (except Gymnophora and Platyphora) pro- 

 vided with several transverse rows of strong marochaetae or bristles. 

 The antennae are placed in cavities at the lower edge of the front, 

 their insertion varying greatly on account of the extreme difference 

 in the length of the front in the various species. The antennal cavi- 

 ties are sometimes more or less coalescent, but usually remain sepa- 

 rated as lateral depressions. The antennae are composed of three 

 joints; of these the first is exceedingly small, and the second is 

 enclosed in the third, so that under an ordinary hand lens they 



