NORTH amp:uican diptkra. 
349 
Ufotes oil ^"ortli American TACHIXII>^E sens. str. with 
ileseriptioiis of new CJenera and Species. 
PAPER II* 
BY C. H. TYLER TOWNSEND. 
The study of the Tachinidse has progressed considerably of late 
in the line of descriptive work. Up to within a few years a large 
number of forms, necessitating the foundation of new genera, had 
remained unnoticed. iNIr. van der Wulp has given us descriptions 
of a considerable number of these, which, however, are mainly con- 
fined to Old Mexico. Messrs. Brauer and von Bergenstamm have 
erected a great number of genera from all parts of the w’orld, some 
of which can be em})loyed ; but many are unfortunately either based 
on invalid characters, or insufficiently de.scribed and without figures 
to enable their recognition. A few other authors have contributed 
isolated descriptions of genera in this grou]). Notwithstanding these 
recent additions I believe it necessary at this time to erect a number 
of new genera for the reception of forms herein described, which 
cannot be reconciled with any of the published descrii»tions or figures 
of previous genera. 
The present jiaper is the result of a study of a considerable col- 
lection of material, all from within the limits of the United States ; 
and will, the writer hopes, contribute toward a more accurate know- 
ledge of our many species among these useful parasitic Hies. 
SIPHOPLAGIAf 11 . gen. 
Belongs in the sub-group with Plagia, from which it differs prin- 
cipally by the elongate, slender proboscis, and absence of bristles on 
the sides of face. Head, thorax and abdomen of nearly equal width 
in the 9 ( ? abdomen narrower in S ). Eyes bare ; front wide, 
prominent ; frontal liristles strong, descending but little below the 
base of antennae ; a strong pair at each vertical angle directed back- 
ward, the outer bristle also directed outward ; three orbital bristles, 
the middle one weak ; first frontal bristle from the vertical pair 
directed outward and backward, the second inward, a little back- 
■* Paper I was published iu the Proc.- Eiit. Soc. Washiiigtou, vol. ii, pp. 134-146. 
t (siphon) -f- Plagia. 
