40 CONNECTICUT GEOL. AND NAT. HIST. SURVEY. [BulL 



legs black to the middle of femora, and beyond the middle 

 of femora yellow-red; antennae black; scutellum and post- 

 scutellum yellow; head yellow in front of ocelli except a 

 black line above each antenna; wings hyaline. Length 

 7 mm \ excavata 



3. Antennae black at base, yellow at apex; body black, with 



head and thorax with the usual yellow markings; legs, 

 except coxae and apical three-fourths of the hinder tibiae, 



pale yellow; wings hyaline. Length 10 mm luteicomis 



Antennae black; body black, with head and thorax with the 

 usual yellow markings; legs, except posterior femora, yel- 

 low; wings hyaline. Length 12 mm pallimacula 



4. Scutellum black; head yellow, with the area behind and in- 



cluding ocelli and between the antennal furrows, black; 

 pronotum, tegulae, and (in female) legs beyond the coxae, 

 yellow; abdomen black with rufous spot covering the disk 

 of second to fourth segments of tergum and venter; anten- 

 nae black; wings strongly infuscated. Male differs in 

 having the apex of the posterior tibiae black. Length 13 



mm plagiata 



Scutellum pale 5 



5. Abdomen rufous beyond the first segment 6 



Abdomen marked with rufous at middle, black at apex 7 



6. Antennae black; mesal projecting spot on the inner margin of 



eye pointed at apex and not bifid; anterior ocellus entirely 

 surrounded by yellow; head and thorax with the usual 

 pale markings; legs yellow beyond the middle of coxae; 

 wings hyaline; the basal half of stigma yellow. Length 12 



mm quebecensis 



Antennae white beyond the middle; mesal projecting spot on 

 the inner margin of eyes deeply bifid at apex; anterior ocel- 

 lus not entirely surrounded by yellow, interrupted by a 

 furrow on each side; head and thorax with the usual pale 

 markings; legs yellow beyond coxae, except posterior tibiae 

 which are black; wings hyaline; stigma black. Length 

 12 mm scripta 



7. Abdomen black, with a rufous spot on the disk of tergal seg- 



ments one to four; head and thorax with the usual pale 

 markings, except that those on the head are reduced t^ fine 

 lines; legs be3^ond coxae, greenish yellow; antennae black; 

 wings hyaline, veins and stigma black. Length 9 mm. 



perplexa 

 Abdomen black at base and apex with a transverse rufous 

 band at middle; legs beyond coxae entirely yellow; trans- 

 verse ridge in front of ocelli and vertex deeply impressed 

 by the antennal furrows; head and thorax with the usual 

 pale markings; second segment of the antennae about 



