1919.] NATURAL SCIENCES OF PHILADELPHIA. 175 



species. It is further characterized by the dark scutellar spines 

 and the longer stigma. The latter in viridis is but little longer than 

 the discal cell and but half again longer than broad. 



9 . Similar to viridis Say. Frons shining, black with slight green- 

 ish tinge, sparingly short white pilose. Face more shining, black 

 with long white pile. Palpi black. Antennae situated below middle 

 of profile, so that the frons is t^vdce as long as the face, black with 

 basal annulus of third joint brownish and distinctly swollen. Thorax 

 and scutellum shining metallic green, becoming black below, sparingly 

 yellow pilose; spines of the latter also metallic colored. Abdomen 

 shining black. Legs yellow, but fore coxae and four apical joints of 

 tarsi black. Wings brownish, veins darker; stigma about twice as 

 long as discal cell, and twice as long as broad. Length, 6 mm. 



Type.— 9 ; Aweme, Manitoba, Canada, July 24, 1911, (E. Griddle), 

 [A. N. S. P. No. 6196]. 



TABANIDiE. 

 Sllvius jonesi new species. 



In general appearance this interesting species does not suggest 

 any affinity with gigantulus Loew, but more critical examination 

 makes it reasonably certain that it belongs to a group including that 

 species and is very distinct from any yet described, to my loiowledge. 

 It is much larger than that species and the abdomen has black or 

 dark bases to all segments. The tibial and antennal characters 

 certainly place this species in Silvius, although in general appearance 

 it suggests some of those in Pangonia. The eyes are uniformally 

 green when moistened. 



cf . Black; antennae except four black terminal annuli of third 

 joint, palpi, abdomen except dark bases of dorsal and ventral seg- 

 ments especially towards apex of abdomen, femora except bases, 

 bases of tibiae, tawny or brown. Halteres pale. Wings blackish, 

 more intense along costa. Subopaque. Yellow pruinose above, 

 becoming gray below. All pile on head and thorax yellow and 

 rather abundant, also on the narrow apices of abdominal segments; 

 the broad bases of the segments with appressed black pile, similar 

 on venter. Femora with pale pile which on the tibiae becomes 

 darker. Pile on first antennal joint and base of palpi, yellow; on 

 second, and apices of palpi, black. No mesonotal vittae. No denuded 

 areas on face. Proboscis not longer than head, and palpi is slightly 

 more than half as long as proboscis. First antennal joint twice as 

 long as second; third twice as long as first and second together; the 



