222 Wisconsin Academy of Sciences, Arts, and Letters. 
74. Face transversely arched, not produced, not tuberculate; abdo¬ 
men more or less elongate and nearly bare. 75 
More or less thickly pilose species, often large. 76 
75. Hind femora extraordinarily thickened; anterior cross-vein rect¬ 
angular, and before the middle of discal cell (see 33)___ 
Hind femora distinctly thickened, but the cross-vein distinctly 
oblique, and near or beyond middle of discal cell. 
.......Xylota (p. 246) 
16 . Scutellum, margin of thorax, and pleurae with distinct bristles, 
femora slender (Chrysochlamys) .*Ferdinandea 
No bristles anywhere on body. 77 
77. Face short, not produced, concave from antennae to oral mar¬ 
gin, not tuberculate; hind femora thickened. 78 
Face produced, long. 79 
78. Abdomen elongate. Brachypalptts (p. 247) 
Abdomen very broad; thorax densely pilose; middle femora of 
male sometimes (Hadromyia) with a stout, basal, inferior 
spur..... *Pocota 
79. Face produced forwards, pointed, concave from antennae to tip, 
not tuberculate; hind femora thickened. Crioprora (p. 247) 
Face not evenly concave in profile, but tuberculate or convex.... 80 
80. Third joint of antennae produced above into an anteriorly di¬ 
rected, conical process, terminating in the thickened 
arista .*Merapioidus 
Third joint of antennae obliquely oval; hind femora rarely 
thickened . Criorhina (p. 247) 
81. Hind femora with a conical, tooth-like protuberance below near 
distal end; antennae more or less elongated; sixth vein di¬ 
rected obliquely outward beyond anal cell.SpiLOMYiA (p. 248) 
Hind femora without much protuberance; sixth vein beyond 
anal cell not unusual. 82 
82. Antennae inserted low down, near middle of head in profile, 
the face not longer than front. Temnostoma (p. 248) 
Antennae inserted on a conical process; front short, the face 
much produced downward; antennae long or short... 
... *Sphecomyia 
Microdon Meigen 
Hind metatarsi slightly or not at all thickened; third segment of 
antennae nearly as long as the first; scutellum with apex emar- 
ginate and armed on each side with a minute tooth of the same 
color; dark-colored species . tristis 
Hind metatarsi of male greatly dilated; third joint of antennae 
shorter than the first; scutellum large, trapezoidal in shape, 
wholly without spines or tubercles ... (gloUosus) 
1. M. tristis Loew. One female Dane County (Marshall), Mil¬ 
waukee County (Graenicher). Figures 1, 2. 
(M. globosus) Fabr. Mich., N. J., Fla., Car., Tex. Figure 3. 
