248 THE CANADIAN ENTOMOLOGIST 



3. Distal antennal joint about .58 mm. in 



length Myzocallis pasanicB Davidson. 



Distal antennal joint about .34 mm. in length 4. 



4. Distal sensorium of antennal III at or beyond middle cf 



joint Myzocallis californicus Baker. 



Distal sensorium of antennal III hardly one- third of the length of the joint 



from base Myzocallis californicus Baker var pallidus var nov. 



Myzocallis californicus Baker var. pallidus var. nov. 



This form differs from var californicus in the sensoriation of the third 

 antennal joint, pallidus having 3 or 4 sensoria all in the basal third of the joint, 

 whereas californicus has from 4 to 6 sensoria more widely distributed and oc- 

 cupying the basal half or more of the joint The structure of the body includ- 

 ing the dorsal tubercles is very similar 



Var pallidus is pale green in colour, smaller in body than californicus ; it 

 was collected January 5, 1918, on Quercus dumosa Nutt , an evergreen scrub 

 oak, near Jacumba, Cal. 



A NEW SPECIES OF THE GENUS TACHYDROMIA FROM ILLINOIS 



(DIPTERA, EMPIDID^). 



BY J. R. MALLOCH, URBANA, ILL. 



The type series of the species described herein is deposited in the collec- 

 tion of the Illinois State Natural History Survey. 



Tachydromia harti, sp. n. 



Male and female.- — -Glossy dark brown. Head black; antennae yellowish 

 testaceous; palpi brown.. Thorax brown, paler anteriorly; propleura with 

 white pruinescence. Abdomen yellowish at base of venter. Legs yellowish 

 testaceous, darker in female, hind femora and tibiae except bases, mid tibiae 

 at bases, and apices of basal three and all of apical two joints cf all tarsi in 

 both sexes blackened; fore tibia in male with two deep black spots on the inner 

 or anterior side, one, heart-shaped, beyond middle and the other, round, at 

 apex. Wing with two broad, black fasciae as in schwarzi Ccquillett, but the 

 apical fascia extending nearer to apex of wing. Knobs cf halteres white. 



Eyes distinctly separated in both sexes; third antennal jcint not large 

 than second; arista terminal., Dorsum cf thorax nude; scutellum with two 

 bristles. Ventral sclerite of abdomen in male in front of hypopygium with a 

 number of curved bristles, apex of hypopygium with a few similar bristles. 

 Fore femur much swollen; fore tibia cf male very much dilated from base to 

 apex. Venation as in schwarzi. 



Length 1.5-2 mm. 



Type— male, Havana, 111., June 5, 1918, (J. R. Malloch). Allotype and 

 paratypes topotypical. One male and three females. 



This species is mcst closely allied to schwarzi Ccquillett, but may be sep- 

 arated from it by the broadened fore tibia of the male and the very much closer 

 approximation of the subapical fascia to the apex of the wing. 



Named in honour of my late colleague, C. A. Hart, who did some of his best 

 work in the locality where the species was taken. 



November, 1919 



