WILLISTON: NEW DIPTERA. 77 



across the middle bluish black; pile in front and behind and on the 

 scutellum light yellow; across the middle of the dorsum black; pile 

 of pleurae black. Abdomen shining steel-blue, with light purplish 

 reflections; first and second segments broadly opatpie in the middle; 

 pile abundant and moderately long, on the first and second segments 

 light yellow, on the remainder of the abdomen black. Legs black, 

 the hind tibiae and the tarsi in large part reddish. Wings somewhat 

 brownish in front. 



Length, 12 mm. 



One specimen, California. This species is nearest allied to C. 

 occidc'titalis ^ill. 



Hystrichodexia Roederi, n. sp. 



Male. Head pale golden yellow; thorax yellowish dusted; abdomen 

 black, with the third, fourth and fifth segments opaque golden yellow. 

 Front much narrowed behind, at the vertex scarcely one-fifth of the 

 width of the head; frontal stripe reddish; sides of the front, the face 

 and the cheeks light golden yellow. Antennae reddish yellow; second 

 joint a little prominent; third joint four or five times the length of the 

 second, slender; aris'a brown, thickened at the base. Proboscis 

 black, longer than the head, slender, labella very small; palpi slender, 

 slightly thickened near the end, yellow, with small black bristles. 

 Dorsum of thorax, when seen from behind, opaque golden yellow, 

 with four slender strijjes, the lateral ones composed of two elongated 

 spots; when seen from in front the golden color is not conspicuous. 

 Scutellum more shining, the tip a little yellowish. Tegulae blackish. 

 First and second segments of the abdomen deep reddish black, 

 shining, clothed with short, recumbent bristles; second segment pos- 

 teriorly with six approximated, stout, erect macrochaetae; the hind 

 margin of the second segment, the third segment, save a lateral 

 marginal spot, and the remaining segments almost wholly, opaque 

 light golden yellow; third segment with a posterior girdle of macro- 

 chaetae, the fourth with a similar girdle beyond the middle; the third 

 segment in front has recumbent black bristles; from the bristles of 

 this segment nearly to those of the fourth the surface is entirely 

 smooth. Venter piceous black, the second segment, at least, with a 

 silvery white pollinose spot on, each side. Legs black; front femora 

 with a comb-like row of long bristles above and below; hind tibiae 

 short,, ciliate without; pulvilli and claws small, the former yellow. 

 Wings brown on the basal costal portion, nearly hyaline elsewhere; 

 antepenultimate section of the fourth vein longer than the penultimate 

 section; ultimate section gently sinuous. 



Length, 14 mm. 



