DURHAM DIPTERA. 1 03 



XVII. 160. 



2 (1). Legs mostly yellow. 



3 (4). Wings with brown spots and bands. 



932. Atherix ibis, F. 

 Taken by Mr. C. Robson in Northumberland. 



4 (3). Wings clouded, not spotted. (933- crassipes, Mg.) 



162. Symphoromyia, Frfld. 



1 (2). Wings dark brown. (936. melcena, Mg.; 



2 (1). Wings quite clear, or only very slightly brown. 



3 (4). First antennal joint very thick and bristly. 



935. Symphoromyia crassicornis, Pz. 

 Bishop Auckland, 1 $, 10-7-00, 1 $, 15-7-00; 

 Rowley, 1 ?, July, 1904. 



4 (3). First antennal joint scarcely thickened. 



(937. immaculate/,, F.) 



164. Xylophagus, Mg. 



1 (2). V.3 2 much longer than V.3.b., abdomen of the female 



all black. (939* ater, F.) 



2 (1). V.3 2 about equal to V.3.b., abdomen of the female 



red on the middle. (940. ductus, Deg.) 



Family XVIII.— ASILID^E. 



The flies prey on other insects ; the larvee of some species 

 feed apparently on vegetable matter. 



TABLE OF GENERA AND SPECIES. 



1 (22). 0.2. open (V. 5). 



2 (5). Feet without pads. X.5. ends in V.4.b. 



165. Leptogaster, Mg. 



3 (4). Hind femora with a black stripe on each side. Tarsal 



joints black, first, second, and third yellow at the 

 bass. (94i« cylindrica, Deg.) 



