TAXONOMY OP MUSCOIDEAN FLIES — TOWNSKXD 2Q, 



1) Ventral plates free, or not so; or that of second segment in both sexes 

 with its edges upon and covering the edges of the corresponding dorsal plate, 

 the other ventral plates free, or this true of only one sex; how many ventral 

 plates, last one in male deeply or weakly Y-cleft or V-cleft, or entire. 



2) Ventral carina present in female, absent, rudimentary, more or less 

 developed, emafgination of plates of same, or latter entire. 



2) Ovipositor elongate, short, tapering, stout, furnished with terminal hooks, 

 appressed, exserted ; directed downward, or forward, or posteriorly; integu- 

 mental, membranaceous, or horny. 



2) Hypopycium prominently exserted, elongate, appressed, directed down- 

 ward, short, rounded, bulb-like, tube-like, of what formation and character- 

 istics. 



(Legs) 



1)2) Legs strongly elongate, only moderately so, short, or only one pair 

 elongate, relative length of pairs; bristly, bare, shaggy-haired, with or without 

 macrochsetse. 



2) Hind femora ciliate or not so, character and position of the cilia. 



2) Hind Tible completely and densely feather-barb-ciliate, only comb-ciliate, 

 subciliate, with some longer bristles; cilia flattened and widened, scale-like, 

 bristle-like, or of what character. 



2) Middle tible with or without strong bristles or macrochsetse on outer 

 side, or on any portion. 



2) Tarsi slender, swollen, compressed, short, elongate, relative length of 

 pairs in each sex; last joint or more of which pairs oval, thickened, swollen, 

 or compressed, in one or both sexes. 



2) Metatarsi short, elongate, comparative length with relation to other 

 tarsal joints of same pair, comparative length of pairs, slender, stout. 



2) Front tarsi widened in female, or widened and flattened, or only flat- 

 tened, in one or both sexes. 



2) Claws and pulvilli elongate in male, or in both sexes, or short in both, 

 or only anterior ones elongate in male ; claws stout, slender, curved, shape and 

 character; pulvilli of what shape and character. 



While the foregoing' enumeration of anatomical parts affording 

 characters of taxonomic value in the superfamily is not necessarily 

 complete, it is believed that it brings out practically all the characters 

 requisite to a proper separation of the forms in the adult. 



Of all these characters, those of the head take first rank. For this 

 reason much space has been devoted to their consideration — in fact, 

 nearly twice as much as to all the other characters together. It is 

 conceded that the Schizophora are the most specialized insects, the 

 most highly developed from the standpoint of ontogeny, as evidenced 

 by their remarkable and practically complete reorganization of larval 

 parts within the nymph. Everything points to the Muscoidea as the 

 most highly organized Schizophora, and this is emphasized by their 

 acute sensory development. It is therefore naturally to be expected 

 that certain non-functional parts of the head, which is the chief seat 



