DIPTERA OF BAJA CALIFORNIA. 609 



brownish yellow. Thorax and scutellum, and lower 

 pleurae, brownish black. Legs yellowish brown, tarsi 

 darker. Head black, thorax with short yellowish pubes- 

 cence. Tegula? obscure whitish, or with a fuscous tinge, 

 possessing a well-defined narrow dark brown border. 

 Knob of halteres brown. Abdomen brownish, hind bor- 

 ders of segments yellowish white. Wings subhyaline, 

 costal margin brown distally and more yellowish basally. 



This species differs from O. pallidipemiis Lw. in the 

 blackish scutellum, yellowish outer humeral callosities 

 and pleurse, and more distinctly margined tegulae. From 

 O. mclampus Lw., it differs in the yellowish humeral and 

 prescutellar callosities, yellowish pleurae and much smaller 

 size and lighter coloring. 



The notes on the following two species of Oncodes col- 

 lected by myself, are introduced here by kind permission 

 of the Academy, while on the subject of this family. 



30. Oncodes melampus Loew. San Francisco Mt., 

 Arizona. One specimen taken in fir zone, July 15. It 

 agrees well with Loew's description. Wings hyahne, 

 tegul« watery white and blackish margined. Wing veins 

 brown. Legs brownish black. Length, about 6 mm.; 

 of wing, 6^ mm. 



This species was described from California. 



31. Oncodes pallidipennis Loew. Dixie Landing, 

 Va., May 25, a very light brownish yellow specimen; 

 and Washington, D. C, June i, a normal brown speci- 

 men. The lighter yellowish specimen is apparently only 

 an immature individual. 



I refer these somewhat doubtfully to this species on 

 the distinctions given by Loew (Centur., vi, 32), other- 

 wise I would be inclined to refer them to O. dispar Macq. 

 The tegulte are more whitish than yellowish, very nar- 



