G8 
evidently ii synonym of mcridionah Hiley; ihcorum Walk, of vittatum 
Zett.; and moUstion llarris equals ccnustnm Say. 
In several species the color of the femora varies from yellow with 
brown tii)8 to wholly brown. The knob of the halteres is always yel- 
low. In the female the; abdomen consists of ei«^ht sej;:ments, but there 
is an additional one in the male. Illustrations 
of the female of inrtNtistKni, and of the male of 
mi'iidionidv are reproduced in ligures 10 and 17. 
With the exception of argus Williston, which 
is unknown to the writer, the following table 
i^^^^^^^2^^^ c(Uitains all the species known to occur in the 
'f/^'^'Z^/ United States, all of which are represented by 
_ ^_ both sexes in the National Museum collection. 
I^xfl^ TAllLK OF THE SPECIES OF SIMULIIM. 
1, Thorax largely or wholly blackish 2 
Thorax and entire insect yellow, the head, abdo- 
men, and tarsi soraetinu's blackish; length, 3'"'". 
Custer Co., Colo., and liearPawMts., M<»nt. 
Fkj. l^.—Himxilxum inrentntum: orhraanm Walk, 
female Hy. eular-e<l (utter g. Hind tarsi distinctly bicolorous, yellowish and 
Riley; R..pt.Dept.Agr. 1886). ^^^,^;,^ [ : 4 
Hind and other tarsi and all legs unicolorous, yellow, brown, or black 3 
3. Abdomen of female gray, marked with a velvet-black fascia on segments 3 and 4, 
and sometimes with two subdorsal spots of the same color on 2, 5, and <>; 
thorax bluish gray, with three black vittie; mesouotum of male velvet black, 
unmarked; the dorsum of abdomen of the same color, marked with a gray 
spot on sides of segments 3, 0, 7, and 8; length, 1.5 to 2'""'. Boston, Mass.; 
Agricultural College. Mississippi: Texas and Nebraska meridionale Riley. 
Abdomen of female grayish brown or black, the sides marked with a row of vel- 
vet-black spots; mesonotum grayish brown, marked with three darker vitta*; 
mesouotum and abdomen of male grayish brown, 
unmarked; length, 2 to 5""". White Mountains, 
New Hampshire; Catskill Mountains, New York 
(May); Adirondack Mountains, New York (May); 
Wilmuth, N. Y. ; Cambridge, Mass.; Roxbury, 
Conn.; District of Columbia; Grand Ledge, Mich.; 
Lakeview, Miss., and Louisiana. . inveiiusium Walk. 
4. Eyes widely separated ( females) 5 
Kyes contiguous (males) 9 / T 
5. Sixth, and usually the two succeeding segments of 
abdonjen opai^ue, the sixth marked with velvet 
black 6 Fig. \7 .—Simulium mrridio- 
Sixth and two succeeding segments of abdomen sub- "o^- ™al® %• enlarge«l 
shining brown and destitute of velvet-black mark- ^f"*'' ^j}^^' ^^P^ ^''^^■ 
ings, segments 3, 4, and d opa<|ue velvet black ; meso- 
uotum grayish black, not vittate, the sides and front corners light gray ; bases 
of tibi;e usually, of first Joint of the middle and hind tarsi, and sometimes 
bases of femora, yellow; front side of front tibia* metallic silvery; length, L8 
to 3"'™. lieaver Mine, Canada; Tranconia and White Mountains, New Hamp- 
shire; Lake Tlacid, New York; Huron Mountains, Michigan; Minnesota; 
r^'itional Park, Wyoming; Glenora, Hritish Columbia; Wilsons Peak, Cal. ; 
Texas; Louisiana; Lakeview, Miss., and Biscayne Bay, Fla icnmtum Say. 
