TAXONOMY OF MUSCOIDEAN FLIES — TOWNSEND 87 



Length, 3.5 mm. Face, cheeks, parafacials, and parafrontals sil- 

 very, the parafrontals tinged with cinereous. Frontalia, antennae, 

 and legs blackish. Third antennal joint about three and one-half 

 times as long as second. Thorax silvery pollinose with tinge of 

 cinereous abflve ; four narrow linear black vittse, the outer ones in- 

 terrupted at suture, the inner ones abbreviated just behind suture. 

 Scutellum silvery pollinose. Abdomen blackish, the second to 

 fourth segments thickly silvery-cinereous pollinose leaving a median 

 vitta and the hind margins blackish or brown, the vitta not so 

 marked on anal segment. The pollen of abdomen is flecked with 

 numerous small dots marking insertion of bristly hairs. Macro- 

 chaetse in a median marginal pair and a lateral one on first two seg- 

 ments, weaker than the marginal rows on third and anal segments. 



fype.— Cat. No. 11,648, U. S. N. M. 



Subfamily BaumhaueriiNyE 

 Genus Euthyprosopa Townsend 



Euthyprosopa pctiolata Townsend.— There are two pairs of 

 ocellar bristles in this genus, the posterior pair being about same 

 length as frontal bristles. The anterior pair is strongly proclinate, 

 almost appressed ; the posterior pair is slightly reclinate, suberect, 

 and inserted between the two posterior ocelli. 



Subfamily Plagiint.e 

 Genus Plagia Meigen 



Plagia aurifrons Townsend. — This species is from the northeast- 

 ern United States, and is not conspecific with the Mexican ameri- 

 cana van der Wulp. 



Genus Plagiprospherysa Townsend 



Plagiprospherysa valida Townsend. — It is possible that the 

 Presidio specimens referred by van der Wulp to his species parvi- 

 palpis may be conspecific with this species, but the others are likely 

 to prove distinct. 



Genus Heteropterina Macquart 



Heteroptcrina nasoni Coquillett. — This form seems, from an ex- 

 amination of the type, to be quite typical of the genus Heterop- 

 terina. The cheeks are very narrow, not over one-tenth eye height, 

 and the few fine hairs of the normal row on parafacials are almost 

 imperceptible with an ordinary low-power lens, but they are present. 



