388 C. R. OSTEN SACKEN'S PRODROME 



brown, except the nn;il angle, wliicli is gvayisli, the hyaline triangle near the apex, and some hyaline spots in 

 the fifth posterior cell. 

 Length, 7-8 mm. 



Female. Face, including the callosities, yellowish-ferruginous ; front beset with yellow- 

 ish-gray pollen, frontal callosity black ; antenna? : basal two joints reddish, the third black, 

 reddish. at base ; palpi brownish-red. Thorax blackish, with the usual broad grayish me- 

 dian stripe, divided hy a longitudinal black line ; lateral stripes (betw^een the scutellum and 

 the humeri) yellow ; a brown stripe separates the thoracic dorsum from the pleura? ; the 

 latter with two yellow stripes, separated by a dark one. Scutellum reddish, with a blackish 

 spot at the base, which, in some cases, extends as a stri2:)e to the apex, leaving only a yel- 

 low spot on each side of the scutellum. Abdomen yellow, with four longitudinal black 

 stripes of very variable breadth ; in some specimens the intermediate pair of stripes con- 

 sists of a series of disconnected blackish spots on segments 2-5, the lateral pair being obso- 

 lete ; in other specimens the strijDes are continous and l:)roader, the lateral pair beginning 

 sometimes on the second, sometimes only on the third, segment; (the picture of the abdo- 

 men is very like that of C. vitfahis); the two or three last segments are usually blackish; 

 venter yellow anteriorly, blackish posteriori}'. Legs reddish, latter half of front tibiae and 

 front tarsi, black ; tips of the other tarsi and, in some specimens, a considei-able portion of 

 the hind femora, black. Wings brown ; second basal, anal, and fifth posterior cells, anal 

 angle and a triangle on the hind margin, within the second and third posterior cells, hy- 

 aline ; a brown cloud on the last section of the fifth vein. 



Hale. Face yellow, lateral callosities and cheeks black, shining ; facial orbits and the 

 stripe separating the cheeks from the callosities, are covered with a pale fulvous pollen ; 

 palpi black ; antennre black, first joint once and a half as long as the second. Thorax 

 black, with black hairs ; on each side of the dorsum, above the root of the wings, between 

 the humeri and the scutellum, there is a distinct stripe of pollen, with an almost metallic 

 greenish lustre, appearing yellowish in a different light ; the usital median stripe on the dor- 

 sum shows a similar metallic greenish lustre, but darker and without yellow admixture ; (it 

 is almost invisible, unless the light falls obliquely from the side of the abdomen and is 

 easily lost in worn specimens); a shade of the same pollen is visible on the scutellum ; pleu- 

 i-ae with alternately brown and greenish-polllnose stripes. Abdomen brownish black, the 

 lateral edge of the second, often also of the first and third segments, brownish-yellow ; 

 along the middle of the dorsum, especially on segments 3, 4, 5, a faint longitudinal stripe of 

 grayish pollen is visible. Front legs blackish, except the base of the tibite which is brown- 

 ish ; middle pair brownish, except the proximal half of femora and tip of tarsi, Avhich are 

 black ; hind pair brownish, femora and end of tarsi black. Wings altogether blackish, ex- 

 cept the anal angle, which is grayish; a small hyaline triangle occupies the distal half of 

 the second and third posterior cells ; small subhyaline dots are visible on the fourth longi- 

 tudinal vein, before the discal cell and at the proximal end of the fifth posterior cell ; a 

 faint subhyaline streak runs across these two dots and the fifth posterior cell to the posterior 

 margin. 



Ilab. I have two females from Dist. Columbia and Georgia (J. Ridings) ; males from 

 Kentucky (F. G. Sanborn), Missouri (C. V. Riley), and a third specimen without indication 

 of locality. 



