384 NEW YORK STATE MUSEUM 
rupted, the exterior pair spotlike. Each segment of the abdo- 
men with a black dorsal stripe and basally on each side with 
a black spot, the penultimate segment black. Wings whitish 
hyaline; halteres white; legs fuscous black, the front side of 
anterior tibiae, the base of the middle and hind tibiae, and the 
base of the middle and hind metatarsi white. Length 5mm. 
Zetterstedt 
Female. The abdomen gray, bases of segments 3 to 7 or 8 
marked with a velvet-black fascia produced backward in the 
middle and at the ends. Length 2 to 4mm. New York, Minne- 
sota, Nebraska, Kansas, California. 
Male. Hind tarsi bicolorous, mesonotum gray on sides and 
hind margin, center largely velvet-black; without gray streak 
extending inward from humerus; sides of abdominal segments 
4 to 7 with silvery white hairs. Coquillettt 
The markings of the female of this species seem somewhat 
variable. The thoracic markings are usually quite distinct. 
The median stripe is nearly of uniform width excepting at the 
posterior end, where it becomes narrower; the intermediate 
stripes. are J shaped, the extremities larger, the intermediate 
portion usually a hair line, sometimes obsolete; the exterior pair 
usually elongated spots. The abdominal markings are as de- 
scribed by Coquillett, though occasionally there are additional 
disconnected, velvet-black lateral spots, one on each side on seg- 
ments 3, 4 and 7, and a pair on 5 and 6. Sometimes also, owing 
either to the contracted condition of the abdomen or to the 
fasciae being narrow, only the black projections of the fasciae 
are visible on the more posterior segments, giving the appear- 
ance of three spots on each. The legs are often gray; the 
femora and tibiae paler at the base, the tibiae black at tip, the 
tarsi deep black except basal portion of middle and hind meta- 
tarsi. Fore tibiae with one spur, middle and hind with a pair. 
Tarsal claws of female simple. 2 
Some specimens from Brookings S. D., received from Profes- 
sor Aldrich, and which are the males of vittatum, possess 
the following characters: 
Male. Velvety black, antennae and palpi dark brown; dorsum | 
of thorax velvety black with the anterior and lateral margins 
1Bul. 10, n. s. 1898. p.63. 
