MEXICAN MUSCIDAE. 185 
blackish; the black dorsal stripe of the abdomen sometimes very 
broad, the yellow colour being reduced to lateral borders. — 
Length 7—9 mm. 
Hyalomyia munda n. sp. 9. — The whole body thickly 
covered by a yellowish-grey tomentum; front broader than the 
eyes; frontal band, four stripes on the thorax, antennae, and legs, 
black; wings yellowish, the costa somewhat infuscated, the veins 
vellow. — Length 5,25 mm. 
Hyalomyia villosa n. sp. d. — Cinereous; front broader 
than the eyes; antennae, four stripes on the thorax, and abdomen 
black; legs piceous; sides of the abdomen and underside of the hind 
femora densely with yellowish pilosity; wings yellowish, slightly 
infuscated towards the tip, veins yellow. — Length 7 mm. 
Hyalomyia hebes n. sp. 4. — Yellowish-grey; front broader 
than the eyes; frontal band, antennae, four stripes on the thorax, 
abdomen, and legs, black; sides and apex of the abdomen with 
short yellowish hairs; wings greyish, their base, costa and tip 
infuscated; the veins blackish. —- Length 5 mm. 
Hyalomyia ochriceps n. sp. d. — Black; front ochraceous, 
as broad as the eyes; abdomen with metallic reflections; wings 
hyaline, infuscated at the base. — Length 5 mm. 
Hyalomyia argenticeps n. sp. 4. — Head silvery-white; front 
as broad as the eyes; thorax grey with four black stripes; abdomen 
shining black with metallic reflections; legs black ; wings greyish , 
slightly infuscated at the base and along the costa. — 6 mm. 
Hyalomyia nigrens n. sp. 9. — Front trigonal, posteriorly 
with the eyes nearly coalescent; face prominent towards the oral 
margin; thorax cinereous with black stripes; abdomen black, the 
last three segments cinereous wilh the hind margins and a dorsal 
stripe black; legs black; wings greyish, — Length 5 mm. 
