18 AMERICAN BLACK FLIES OR BUFFALO GNATS. 



Prosimulium fulvum Coquillett. 



Female. — Entirely yellow or ocherous; the {intennse except basal 

 three joints, the pleurjv, abdomen, and tarsi more or less brownish. 

 AVinjrs yellowish, the veins distinct. Halteres yellow\ 



Frons rather strongly divergent, at lower angle of eyes about two- 

 fifths as broad as at upper angle; surface hairs long and numerous, 

 golden yellow in color; face slightly broader than frons at lower 

 angle and rather longer than broad, haired as frons; palpi brown- 

 haired; postocular cilia long, yellow, with a strong admixture of 

 l)lack hairs. Mesonotum with longish, yellow, hairlike pilosity, rather 

 .shagg;\' on anterior, lateral, and especially on posterior margins; 

 l^leural tuft yelloAv, continued downward more than midway to 

 coxae; scutellum with long yellow pilosity, and shaggy, upright, 

 yellow hairs. Abdomen with yellow basal fringe, and numerous 

 .^hort yellow surface hairs. I^gs with long yellow hairs, among 

 which are a fcAv dark ones, the tarsal hairs broAvnish ; tarsal chnvs 

 simple (PL II, fig. 13). Wings with surface hairs yellow, the small 

 cell at base of upper fork of cubitus distinct. 



Length, 4—5 mm. 



There are females in the collection from Sitka, Virgins Bay, and 

 Kukak Bay, Alaska ; from Bear Lake, Kokanee Mountains, Kaslo. 

 South Fork, Lowes Inlet, and Laggan, British Columbia, and Cus- 

 ter County, Colo. 



Male. — Similar in size and color to the female, but Avith much 

 longer hairs, especially those forming the fringe to the basal scale, 

 those on surface of abdomen, and those on the legs. The fore tarsus 

 is slender, and the basal joint of hind tarsus is much dilated, being 

 as broad as the apical portion of hind tibia (PI. II, fig. 1) ; the 

 claws are trifid. 



The type specimen (Cat. No. 6182, U. S. National Museum) is 

 from Bear Paw Mountain, Mont., September 3, 1895 (Hubbard). 



Nothing is known of the .life history, or details of the early stages 

 of this species, and there are no records of Avhether or not it bites 

 either man or animals. 



Prosimulium hirtipes Fries. 



Female. — Black, opaque. Antenna^ with two basal joints pale 

 yelloAvish-brown. Scutum unstriped, and AA^ithout any distinct an- 

 terior pollinose spots; prescutum and pleura? sometimes broAvnish. 

 Abdomen Avith basal scale brownish; sometimes the segments appear 

 faintly Avhitish-dusted on posterior margins. Legs broAvn; coxse. 

 knees, tips of tibiso and tarsi, especially fore tarsus, darker. Wings 

 grayish. Halteres broAvn. 



