48 DIPTERA OP NORTH AMERICA. [PART II. 



last joints of the fore tarsi enlarged, and the hind femora not ciliated. 

 Long. corp. 0.26. Long. al. 0.25. 



SYX. Dolichopus tonsus LOEVT, Keue Beitr. VIII, 16, 12. 



Metallic-green, bright. Face of the J* narrow, more light 

 ochre-yellowish than golden-yellow ; the face of the 9 broader and 

 yellowish-white. Antennae entirely black, the lower corner of the 

 first joint only lighter ; the third joint short. Front green, or 

 bluish-green, bright. Cilia of the inferior orbit yellowish. A 

 bronze-colored middle line of the thorax is not distinct ; on each 

 side before the transverse suture a bronze-colored spot. Fore 

 coxa? yellow, upon the anterior side with rather delicate minute 

 black hairs, which gradually disappear towards their base. Hind 

 coxa? only at the extreme tip yellow. Feet yellow ; hind femora 

 with a bristle before the tip. The coloring of the fore tarsi in the 

 9 gradually changes towards the tip into brown and black ; mid- 

 dle and hind tarsi black from the tip of the first joint, still the 

 base of the second joint yellow. Cilia of the tegula? yellowish. 

 Wings grayish-hyaline ; the fourth longitudinal vein not broken. 



Male. Lamella3 of the hypopygium whitish, of medium size and 

 of an elongated ovate form, on the upper and apical margin nar- 

 rowly bordered, with black, on the latter much jagged and fringed 

 with partly black, partly yellowish bristles. Hind femora not 

 ciliated upon the under side. Hind tibia? of ordinary stoutness ; 

 their whole hind side uniformly beset with minute black hairs. 

 The fore tarsi more than 1^ times the length of the tibia? ; the three 

 first joints slender, stalk-like ; the second joint is equal to about 

 two-thirds of the length of the first, and the third to about three- 

 fourths of the length of the second ; the fourth joint is nearly as 

 long as the third, flattened, at the end somewhat broader, still 

 even here not half so broad as long, white, with a handsome sil- 

 very reflection ; upon its upper margin with hardly visible and 

 short minute black hairs ; the fifth joint as long as the fourth, flat- 

 tened, and somewhat broader than the previous one, black, beset 

 upon its upper margin with short and appressed minute black 

 hairs. Costa near the tip of the first longitudinal vein without 

 swelling ; between the apex of the wing and the tip of the fifth 

 longitudinal vein the margin shows a shallow sinus. 



Hob. Washington. (Osten-Sacken.) 



Observation. The 9 of the three species described above are 



