CONNECTANT FORMS BETWEEN THE MUSCOID 
AND ANTHOMYIOID FLIES. 
By CHARLES H. T. TOWNSEND, 
Director of Entomological Stations, Lima, Peru. 
The object of this communication is to point out certain 
forms which appear to be transitional between the muscoid and 
anthomyioid types, to call attention to their evident affinities, 
and to suggest characters which may be used for establishing 
a boundary line between these two natural groups of flies. 
Girschner’s system, proposed in 1893, recognizing two groups 
which he called Tachiniden and Anthomyiden, contains many 
elements of truth. It has resulted in demonstrating muscoid 
affinities in certain forms hitherto accepted without question 
as anthomyioid. Bezzi and Stein have followed this system 
in their catalogue, and Schnabel and Dziedzicki have recently 
attempted to reinforce it in their treatment of the anthomyioid 
flies. What concerns us -chiefly in the present consideration 
is the fact that Musca and its immediate allies fall in the 
Anthomyiden according to this system. The concept is funda- 
mentally wrong nomenclatorially, however it may be justified 
otherwise. Whatever group Musca is found to fall in must 
take its name from that genus. If Girschner’s group Anthomy- 
iden be adhered to as it stands, its name must be Musciden 
according to all accepted rules of nomenclature. But it is 
certain that many characters remain to be investigated before 
this grouping can safely be pronounced a natural one, for the 
main separation is founded practically on a single character— 
the presence or absence of hypopleural bristles. 
The solution of the question practically hinges on whether 
Musca is, or is not, more closely allied to Anthomyia than it 
is to Calliphora. Wherever Musca goes, it will carry with it 
a considerable contingent—Stomoxys, Muscina, Mesembrina, 
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