No. 3.] HYGROCELEUTHUS AND DOLICHOPUS. 



127 



tarsi short, first joint broadly feathered laterally. Wings narrow, hyaline, 

 distinctly yellowish towards costa. The usual costal swelling at tip of first 

 vein is slight. Almost no incision at tip of fifth vein. The anal angle of 

 wing is produced into a large distinct lobe. Veins dark. Bend in fourth 

 vein regular. Halteres and tegulae yellow, the tegular cilia long and black. 



One male specimen taken by Dr. Wm. M. Wheeler in a cran- 

 berry bog at Woods Holl, Mass., July 13, 1899. 



This very distinct species is readily recognized by its length- 

 ened middle tibiae. Aside from this the following are more or 

 less characteristic : the reduced costal swelling and incision of 

 the wing as well as the pronounced anal lobe ; the peculiar lat- 

 eral ornamentation of the middle tarsi, which are unusually 

 short ; the violet front ; the light-colored antennae and finely 

 pubescent arista ; and the yellow hind tibiae. 



Hygroceleuthus plumipes Scopoli. 



Male. Length 3.5-4.5 mm. Length of wing 3.5-4 mm. Face yellow 

 pollinose. Antennae yellow, third joint black at tip. First joint with a 

 slightly prominent projection on its inner side. Arista slightly pubescent. 

 Front metallic green. Thorax without distinct dusted bands. Abdomen 



FIG. 3. H . plumipes : a, male wing ; b, female wing; c, antenna : i/, middle tibia ; 



e, middle metatarsus, male. 



metallic green above and distinctly bronzed toward the apex ; white dusted 

 at the sides and covered throughout with short black hairs. Lamellae of 

 hypopygium narrowly bordered with fuscous. Pleurae metallic green, cov- 

 ered with white dust. Coxae of same color as the pleurae, except the anterior 

 ones, which are yellow and covered with black hairs on the anterior and 

 inner surfaces, bearing also a few black bristles at their tips. Femora yel- 

 low. Tibiae yellow, the middle pair slightly, and the posterior pair dis- 

 tinctly tipped with black. Middle tibiae flat, very slender except at extreme 



