PANGONIA.— CHEYSOPS. 45 



brownish. Wings at the base, up to the alar excision, dark brown ; beyond, up to the 

 central cross-veins and still further along the costa, tinged with yellow, the remainder 

 of the wing being pale brownish ; submarginal cell appendiculate ; first posterior cell 

 closed near the margin, the fourth broadly open. A single male. 



3. Pangonia prasiniventris. 



Pangonia prasiniventris, Macq. Dipt. Ex. Suppl. i. p. 29, t. 3. f. 9 x ; Schiner, Reise d. Novara, Zool. 

 iii. Abth. i. p. 100. 



Hab. Panama, David (Champion). — Colombia. 



Schiner is right in criticising Macquart's description and completing it ; nevertheless 

 the identification is hardly doubtful. Four males. 



CHRYSOPS. 



Chrysops, Meigen, in Illig. Magaz. ii. (1803) . 



l. Chrysops altivagus, sp. n., s $ . (Tab. I. figg. 6 c? , 7 $ .) 



Antennae altogether black, first joint incrassate ; legs black. 



$ . Abdomen grey, with two rows of black spots on the segments ; wings with a black costal margin and 

 cross-band. 



<S . Body altogether black ; wings black, with a hyaline triangle before the apex only. 

 Length 7-8 millim. 



Hab. Mexico, Ciudad in Durango 8000 feet (Forrer). 



Female. Face and front covered with the usual yellowish pollen ; facial callosities 

 shining black on the outer side, yellowish-brown on the inner, the lower part, where they 

 coalesce above the mouth, being black, but in some specimens brownish ; palpi black ; 

 frontal callosity black, transverse, about three times broader than long, separated by a 

 comparatively broad interval from the blackish area of the ocelli. Antennae black ; first 

 joint incrassate (somewhat like the European C. rufipes) ; the second joint but little more 

 than half so long as the first, stout ; the third joint about equal in length to the first two 

 together, rather stout. Mesonotum and scutellum black, moderately shining, clothed 

 with scattered, erect, yellowish hairs (often rubbed off) ; a faint greyish stripe, bisected 

 by a black longitudinal line, is visible in front ; more distinct stripes of greyish pollen 

 along the sides, above the dorso-pleural suture; pleurae greyish-pollinose. Abdomen 

 greenish-grey, yellowish pubescent ; the sides of segments 1 and 2 more or less yellow ; 

 the middle of the first segment black ; in the middle of each of the segments 2-6 a pair 

 of black, semioval spots, contiguous to the anterior margin only, not to each other, 

 those on segment 6 nearly obsolete ; on each side of these spots, on segments 3-5, other, 

 smaller black spots are visible, variable in size, sometimes coalescing with the central 

 spots ; venter grey, yellowish pubescent. Legs black, yellowish-pubescent, especially 

 on the tibiae ; intermediate tibiae slightly reddish at the base. The black costal border of 



