168 
Psyche 
[December 
narrow ; venation much as in V. comstocki, but the anterior 
branch (R 4) of the third longitudinal vein is more curved 
at the tip, the fourth posterior cell (M3) is closed near 
the wing margin, forming a very short M3 -f Cu vein, 
and the apex of the first anal cell is so greatly contracted as 
to be almost closed. In V. vermiieo the tips of the fourth 
posterior and first anal cell are contracted but not closed. 
Fore and hind tibiae with a single stout spur ; middle tibise 
with two spurs. Abdomen long and narrow, tapering at 
the tip ; genital appendages small, the outer pair short and 
broadly excised distally, with rather acute anterior tips. 
Male (living) . Length 9.5-10 mm. ; wing 8 mm. 
Differing from the female in its smaller size and more 
slender stature, the thorax being decidedly narrower than 
the head and less convex dorsally, and the abdomen much 
more slender and clavately enlarged at the tip, though the 
genitalia are small. Face and front not narrower than in 
the female, but the two basal joints of the antennse are dis- 
tinctly broader, shorter and more flattened. 
Mounted specimens of this fly soon lose their rich fulvous 
color and become dull reddish and the eyes dark brown. 
The glistening white dust on the thorax and coxae is absent 
or poorly developed in some recently emerged individuals. 
According to Walker the male of the Jamaican tibialis 
measures 4 lines (8.3 mm.) though the wings measure 
7 lines (about 12 mm.). The former measurement may be 
readily explained as due to the shrinkage of the abdomen 
in drying, but the latter exceeds that of the females of 
the Cuban specimens. The Jamaican form, moreover, 
seems to have an entirely black antennal arista, the hai- 
teres having dark-colored knobs, the markings on the wings 
are brown instead of blue-black, and there is no dark spot 
near the apex of the hind femora. Walker's figure shows 
two spurs on the fore and hind, as well as on the middle 
tibise, but this may be a draughtsman's error. 
Williston's description shows that the Mexican Vermiieo 
fascipennis differs from tibialis in having the face bare, 
the dorsal portions of the three antennal joints as well 
