170 DIPTEEA. 



2. Dizonias ? 



Edb. Mexico, Northern Sonora (Morrison). 



A single male, black, with the abdomen, except the dorsal side of the two basal 

 segments, red. I do not perceive any white cross-bands on the abdomen. This speci- 

 men cannot therefore be identified with the descriptions of either B. phamicurus, Loew, 

 Cent. vii. no. 53 (Mexico, Tamaulipas), or B. (Basypogon) lucasi, Bellardi, Saggio &c. 

 ii. p. 81, 1. 1. f. 7 (Mexico) ; nevertheless, it may be merely a variety of either. 



STICHOPOGON. 



Stichopogon, Loew, Linn. Ent. ii. p. 500 (1847). 



1. Stichopogon catulus, sp. n., s . 



Abdomen black, the front angles of segments 2-7 filled up with large triangles of grey pollen. 

 Length 5-5-6-5 millim. 



Edb. Mexico, Northern Sonora (Morrison). 



Face silvery, the beard and mystax white ; front and occiput black, thinly greyish- 

 pollinose; antenna? black. Thorax and legs with a thin greyish pollen on black 

 ground ; the sides of the thoracic dorsum, along the dorso-pleural suture, having, in a 

 certain light, a white reflection ; pleurae hoary pollinose. Abdomen black ; segment 1 

 greyish on the sides ; segments 2-7 each with a large grey-pollinose triangle in the 

 anterior corners, one of the angles of the triangle reaching the hind margin, the other 

 quite or nearly touching the corresponding angle of the opposite side ; eighth segment 

 grey. Halteres pale yellowish ; tip of the knob sometimes darker. Wings hyaline. I 

 have two specimens from the above locality. 



2. Stichopogon trifasciatus. 



Dasypogon trifasciatus, Say, Proc. Acad. Phil. iii. p. 51 1 ; Compl. Wr. ii. p. 64; Wiedem. Aussereur. 



zweifl. Ins. i. p. 405. 

 Thereva plagiata, Harris, Catal. Ins. Mass. ; Walker, List &c. i. p. 223 2 . 



Eab. United States 1 2 . — Mexico, Northern Sonora (Morrison). 

 A single specimen from Sonora. 



3. Stichopogon ? 



Edb. Mexico, Northern Sonora (Morrison). 



A single specimen of an almost uniform dingy greyish colour cannot be referred to 

 any of the described species. 



