194 DURHAM DIPTERA. 



XXVIII. 289. 



d (a). Pubescence of scutellum yellow. 



var. tceniata, Mg. 

 Wearhead, i $, 2-8-01 ; Hesleden, 1 $, 7-8-02. 



4 (1). Thorax brightly shining, with its side-margins usually 

 interrupted about the suture. Small species, 6^ mm. 

 Scutellum usually yellow haired. 



(1548. flavicauda, Ztt.) 

 a (b). Femora yellow. (v r ar. flavicauda, Ztt.) 



b (a). Femora considerably blackish. 



(var. nitidicollis, Ztt.) 



290. Xanthogramma, Schin. 



1 (2). Basal abdominal spots broad and triangular ; hind 



femora and tibiae with dark rings. 



(1549. ornatum, Mg.) 

 2(1). Basal abdominal spots narrow and linear; hind legs 



all orange. ( I 55°- citrofasciatum, Deg.) 



292. Baccha, F. 



1 (2). Male frons very shining ; female frons shining above 



the antennae. ( I 55 2 - obscuripennis, Mg.) 



2 (1). Male frons dusted ; female frons dusted above antennae. 



Baccha elongata, F. 

 Hesleden, 2 $, 7 % August, 1899-00; Bishop Auck- 

 land, 3 ?, 19-8-97, 1 1-6-00, 24-6-02. 



295. Sphegina, Mg. 

 1556. Sphegina clunifies, Fin. 

 Shipley, 1 ?, 17-7-00. 



296. Ascia, Mg. 



1 (2). Wings with a darkish band and the X-veins clouded 

 lower outer angle of 0.4 2 almost a right angle. 

 . 1557. Ascia podagrica, F. 

 Common everywhere. 



