294 Mr. W. Wesclu; on sysicinatic afmitici of Ike Phoridaj 



classiucatiuii. Tlio Lejjtida' coine next, as tlieir mouth 

 parts are nearly identical with those of the Louchopterida'. 

 Tliou cotne the Strationiyidn-, Tabanida', Bonibylida*, 

 Therevida' and Scennpinida' in their usual order, and the 

 Cyrtida3 close the list in the Orthorrapha, occupying a 

 position where their vei'y large teguhv do not seem at all out 

 of place. It will be seen by this rearrangement that the first, 

 second and third families possess the striking character of 

 the process in the pharynx, the third, fourth and fifth, 

 the equally striking character of the peculiar articulation 

 of the antenna', while the fourth, fifth, sixth and seventh 

 have chitinous plates on the paraglossie, and from the 

 second to the seventh family (the Stratiomyida^) all six 

 have the mandibles embedded on the ventral side. 



Affinities between the PnoiiiD.E and the Doli- 



CHOPODID/E. 



1. General morphology. — The thorax and the coxa\ 

 particularly the fore coxa% arc often similar, and the legs 

 are sometimes much alike. 



2. AntenN/E. — The Dolichopodida\ Phorida', and Lon- 

 chopteridai have a common peculiar articulation of the 

 third joint, discussed more at length in the earlier part of 

 the paper. 



3. Characters in the mouth parts. — (a) In Boh'- 

 chopus the mandibles are also embedded on the ventral 

 side, on the median line of the mentum. (h) What re- 

 mains of the maxillaj instead of remaining in the base 

 of the labium as is almost invariably the case, occupy 

 a very anterior position, as far as my observations go — a 

 uni([ue position and a character confined to the two 

 famihes. (c) There are only two other families in Diptera 

 in which the labrum is armed, the Doliciiopodida' and the 

 Empidie. {d) On the labrum of many species of Phorida', 

 high powers show a decided pubescence. The hairy 

 nature of the labrum is a peculiar character of the Doli- 

 chopodida;. (c) The hypopharynx is strong, deeply 

 channelled, and viewed laterally is more like its homo- 

 logue in DolichoimH than in any other family. (/) The 

 palpi are large, and bear a number of bristles, and similar 

 conditions exist in many Dolichopodidai. {g) The taste 

 hairs are similarly arranged, and are larger than in the 

 Muscidse. 



