384 NEW YORK STATE MUSEUM 



rupted, the exterior pair spotlike. Each segment of the abdo- 

 nieu -with a black dorsal stripe and basallv on each side with 

 a bliick 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 3mm. 

 Zetterstedt 



Female. The abdomen grav. 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. Kew York, Minne- 

 sota, Xebraska, 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. Coquillett^ 



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 arey" 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, onlj^ 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. 



Some specimens from Brookings S. D., received from Profes- 

 sor Aldrich, and which are the males of v i 1 1 a t n m , possess 

 the following characters: 



Male. Velvety black, antennae and palpi dark brown; dorsum 

 of thorax velvetv black with the anterior and lateral margins 



iBul. 10, n. s. 1898. p.63. 



