NORTH AMERICAN DIPTERA. 239 



character also prevails on the middle tibiae ; tips of tlie femora, base of the tibiaj 

 and tarsi yellow, tarsal joints annulated with red at the ti])s. Wings brown, 

 veins red, tips more or less a clear hyaline. 



9 . — Face, front and vertex black, whitish pile longest and thickest on the face, 

 front shining, a spot on the facial orbits, a small subcordate spot below the ocelli 

 and the lower part of the occiput yellow ; in some specimens there is also a very 

 small spot on each side of the ocelli. Thorax black, with black and whitish 

 tomentum, arranged so as to form a broad dorsal and transverse line and a post- 

 alar spot of black. Abdomen black, with short whitish pubescence ; the yellow 

 markings on the second, third and fourth segments consists of a small subtrian- 

 gular at the anterior angles, a narrow lateral margin more or less distinct, and 

 narrow transverse markings at the lateral posterior margin, fifth with a lateral 

 margin widest anteriorly, and a dorsal stripe not reaching the anterior margin ; 

 venter greenish yellow, with black markings similar to those of the male, but 

 usually larger, leaving only a narrow lateral and posterior margin of yellow. 



Over forty specimens ; southeastern Pennsylvania and southern 

 New Jersey; couuuon July 5 to August 16; West Pt., Neb., June 

 (Al(irich) ; Riley County, Kansas, June (Marlatt) ; Blanco County, 

 Texas; Agricultural College, Michigan, June 20 (Davis); Algon- 

 quin, 111., June 4 (Dr. Nason). 



Loew's descriptions were based on single specijnens ; with a large 

 series it would have been impossible to separate them. The type of 

 S. angularis differs from S. marginalis in having more prominent 

 yellow triangles at the anterior angles of the segments, and S. nigrl- 

 veutris in having a greater amount of black on the ventral segments. 

 The specimen referred to, S. Melgenli, has the yellow spot on the 

 front, and the yellow of the scutellum prominent. Wiedemann 

 describes a % , but the head in the figure is that of a 9 • In the 

 figure the abdomen shows only four segments, or at least the color 

 markings indicate only four, while the vittee on the fifth segment 

 extends from the anterior margin and does not reach the posterior ; 

 the latter is the reverse in all our Stratlomgia, so that the figure 

 should be considered incorrect. 



^ttratioiiiyia apicula Loew, (PI. iii, figs. 23, 24). 

 Stndiomi/ia apicula Loew, Centur. vi, 13. 

 Length % 9 l'~ "lui- % .—Face, frontal and vertical triangles black ; pile on 

 the face white ; facial orbits slightly yellowish. Antennae black, underside of the 

 third and tip of the second joint brown. Thorax black, with yellowish white 

 pile ; scutellum black, apical margin and spines yellow. Abdomen black, with 

 short whitish pubescence, and with the following yellow marking on each of the 

 segments : a small lateral spot on the first, a large subquadrate marking at the 

 sides of the second ; third with a wide lateral posterior margin of about equal 

 extent ; fourth with a lateral margin, widest anteriorly and slightly extending 



TEANS. AM. KNT. SOC. XXII. JULY, 1895. 



