364 CHARLES T. BRUES. 



Yellowish, the color of the thorax often varying into red, sometimes into 

 brown. Head black; front wide, subeouvex, lightly punctulate, with a very 

 faint, median, longitudinal, impressed line; the anterior setae directed down- 

 ward. Antennae black, in immature specimens brown ; palpi yellow. Pleurae 

 below the wings and between the middle and hind coxae generally with black 

 markings. Metanotum generally brown or blackish. Abdomen in immature 

 specimens wholly clay-yellow, in mature ones the first segments, except the pos- 

 terior margins, almost entirely brown, the remainder with brown sides. Feet 

 pale yellowish, extreme apex of the hind femora black, front tibiae without 

 setae, the others with a single row of very minute setulae above. Halteres yel- 

 low; wings subbyaline, very slightly tinged with grayish yellow; costa with 

 small cilia; veins brown, second heavy one forked, the fourth light one entire 

 and distinct. 



Original description translated. 



Thorax with two dorsocentral niacrochsetse and four marginal 

 scutellar bristles. Cheeks each with two stout macrochsetfe. First 

 vein ending midway between humeral cross vein and tip of third 

 vein ; costa ending beyond the middle of the wing, its bristles rather 

 short. Palpi of 1 with very small bristles and distinctly enlarged. 



This form is related to P. picta Lehm, but differs by its black 

 head and the longer bristles on the costal vein. 



New Bedford, Mass. (Hough); Algonquin, 111. (Nason) ; Knox- 

 ville, Tenn. (Summers) ; Ithaca, N. Y. ; Austin, Texas, bred from 

 an artificial nest of the ant Pogonomyrrhex barbatus (Wheeler) ; 

 Wood's Hole, Mass. (Brues). 



This is a species which is widely distributed in the eastern part of 

 the country, and is by far the most variable one that I have exam 

 ined. The lateral pair of scutellar bristles varies from extremely 

 small to the size of the other pair. The color also varies greatly. 

 The head is always black, but the rest of the body may be pale yel- 

 low or brownish. 



Specimens from New England and the northern parts of the 

 country are the most typical and agree very well with the original 

 types at Cambridge, with which I have compared them. 



Aphiochsrta scalaris* Loew. (Plate vii, fig. 33.) 

 Loew, Centuries, vii, 100. 

 Length 2.5-2.6 mm. Yellowish, the color of the thorax sometimes a little 

 darker. Head, antennae and palpi yellowish; front broad, subeouvex, finely 

 punctured, and with a fine median impressed line; both pairs of proclinate setae 

 well developed. Pleurae immaculate, dorsum with one pair of dorsocentral 

 macrochsetae .and four marginal scutellar bristles ; metanotum yellowish. Abdo- 

 men luteous or ochraceous, hind margin of first segment narrowly, the side and 

 hind margins of the other segments very broadly black. Legs pale yellow, the 



