206 
The Ohio Naturalist. 
[Vol. XIV, No. 2 , 
other species of Syrphidae. The usual collection does not contain 
very many specimens. The material for this paper was procured 
entirely from Dury’s collection, from R. C. Osborn’s collection 
and from my collection, the latter now largely with the Ohio State 
University collection. All the known North American species 
are represented, but none of them by more than a dozen specimens. 
Key to the North American Species. 
1. Whole body uniform shining black without yellow tomentum 
or ground color. 2. 
Whole body not shining black often either with dense yellow 
tomentum or yellow ground color. 3. 
2. Legs entirely black, bell a. 
Middle and hind legs have the first three tarsal segments of 
each white, nigra. 
3. Whole body uniform brown with very short yellow tomentum. 
Each side of the face below with a luteous spot, strigilata. 
Body not uniform brown, no luteous spots on the face. 4. 
4. Thorax with yellow transverse markings, transversa. 
Thorax without transverse markings. 5. 
5. Ground color of the abdomen marked with yellow on the sides 
of first two or three segments, varipes. 
Ground color of the abdomen not marked with yellow, body 
with more or less yellow tomentum. 6. 
G. Male. Tomentum of the thoracic dorsum long, entirely 
hiding the ground color, abdomen with transverse pollinose 
markings, aurinota. 
Male. Tomentum of the thoracic dorsum short and in rows, 
not concealing the ground color, abdomen without pollinose 
markings, anricaudata. 
Myiolepta bella Williston. One of the largest species of its genus, 
whole body, including the legs, shining black, wings slightly 
fumose. Length 9 millimeters. 
Female: Front and face shining black, not at all pollinose, 
face longer than in the other species of its genus, hollowed out 
so that nearly a uniform curve extends from the base of the 
antennas to the oral margin. Antenna rather short, first two 
segments black third segment nearly round, reddish brown with 
the upper margin darker, arista dark in color and inserted near 
the base. Thorax with sparse hair which is partially light in 
color, but mostly black; hair of the legs largely pale, but some 
black intermixed in places; wings uniform pale fumose all over, 
veins nearly black, first posterior cell closed a little way from the 
margin, the petiole much less than half as long as the anterior 
cross-vein, second vein nearly straight at apex, thus forming a 
distinct acute angle with the costa and differing in this respect 
from the other North American species of its genus. Hair of 
the abdomen pale. 
