Sept., 1913] Melander: Synopsis of Diptera. 271 



ig. Sides of thorax and the humeri broadly yellow. (Eur.;* Id.,* Wash.*) 



bipiinctata Loew. 

 Notopleural suture narrowly yellow, humeri not yellow 20. 



20. Mesonotum, pleurae and abdomen subshining; bristles fine; arista short- 



pubescent. (Eur.; Conn.,* D. C, 111.,* Id.*) aquilegia Hardy. 



Notum and pleurse opaque cinereous black ; bristles coarse 21. 



21. Arista much thickened and closely pubescent; usually three fronto-orbitals. 



(Eur. ; Id.,* Wash.*) crassiseta Zetterstedt. 



Arista slender, as usual 22. 



22. Arostichals present; ovipositor longer than the last abdominal segment. 23. 

 Acrostichals absent ; ovipositor shorter than the last segment ; incisures 



yeftow. (N. Y., Mass.,* Conn., Pa., N. J., B. C.*) .chrysanthemi Kowarz. 



23. Incisures of the abdomen conspicuously yellow. (Eur. ;* Greenl., Id.*) 



(solita Walker ?) affinis Fallen. 



Incisures not yellow, only the last segment banded. (Eur.;* Mass., N. Y., 

 D. C, Ont., Id.,* Ore.,* Wash.,* Cal.*) (genualis Loew.) 



albiceps Meigen. 

 Phytomyza orbitalis new species. 



1^5. Length 1.5 mm. Black, with a slight brownish tinge, lightly dusted. 

 Frontal orbits marked with a yellow stripe bearing the bristles. Proboscis, 

 notopleural suture broadly, humeri, some of the abdominal incisures narrowly, 

 knees, tarsi and root of wings more or less dark brownish. Humeral callus 

 sometimes yellowish. Halteres whitish yellow. Four fronto-orbitals ; center 

 of front opaque, but sometimes brownish ; cheeks one sixth the eye-height ; 

 vibrissa not much stronger than the oral hairs; third joint of antennas rounded- 

 ovate, scarcely pubescent, the arista microscopically pubescent, two times the 

 length of the third antennal joint. Five dorsocentrals, of which one is pre- 

 sutural, but the anterior three weak and scarcely differentiated from the 

 setulae ; four scattered rows of acrostichals ; two sternopleurals, the large meso- 

 pleural near the top of the row. Last abdominal segment short, conical. 

 Fringe of calypteres dusky ; wings nearly hyaline, the fourth vein nearly 

 straight, ending beyond the wing tip, the third section of the costa but little 

 shorter than the following section. 



Twenty-two specimens, from Collins, Troy and Moscow Mountain, 

 Idaho, and from Pullman, Kamiac Butte and Oroville, Washington; 

 May to August, but most of the specimens taken in June. 



The species is structurally very much like ohscurclla Fallen. The 

 arista, however, is more slender and less perceptibly pubescent, the 

 cheeks are narrower and the dorsocentrals are less pronounced. 



Phytomyza nitida new species. 



1^ 5- Length 1.3 mm. Black, rather shining, the proboscis, halteres and 

 root of wing whitish. Two or three fronto-orbitals ; the vibrissa no longer 



