SYNOPSIS OF NORTH AMERICAN SYRPHID^. 15 



low of the posterior margin beliiud. Margin of the abdomen from the 

 second segment yellow ; the black spot on the fifth segment is slender, 

 forming three arms; the basal one is short, formed by the interruption 

 of the arcuate band; the two posterior are curved outwardly, so that 

 the distance between the tips is about the same as the length of each. 

 Legs yellow. Wings with a narrow brown border in front. 

 Three specimens, New Mexico (G. F. Gaumer), from Mr. Eugene Keen. 



Chrysotoxum pubescens. 



Crysotoxum puheacens Loew, Wien. Eut. Monatschr., iv. 84; Centur.,v. 43. 



Habitat. — Illinois (Lw.), New York!. 



5,9. Length, 12,5°''". Second joint of the antennae longer than 

 the first; the third joint in the female subequal to the two preceding 

 together; in the male longer. Eyes pilose. Lateral stripes of the 

 thorax interrupted; the median vittulae conspicuously whitish pollinose. 

 Scutellum yellow, the disk black. The yellow fasciai of the abdomen of 

 moderate width, arcuate, interrupted, on the posterior angles of the seg- 

 ments connected with the posterior bauds ; these hind margins on the pos- 

 terior segments are broader than on the anterior segments, on the last 

 segment dilated into a triangular spot between which and the fascia the 

 black forms an inverted V. Venter black, posterior margin of the seg- 

 ments yellow ; the two intermediate in the male, the last three segments 

 in the female, each with two ovate yellow spots. Hypopygium yellow. 

 Legs yellow. Wings cinereous ; near the costa, lutescent. 



Translation, compared with the types. Specimens agreeing with this 

 I have seen from New York. 



Chrysotoxum veutricosum. 



Chrysoloxum ventricosum Loew, Centur., v, 44. 



Habitat. — District of Columbia (Lw.), Canada! 



5 . Eyes pubescent, scutellum wholly yellow, abdomen globose, with 

 fasciae of moderate width, moderately arcuated, narrowly separated or 

 subseparated from the lateral margin; base of the front and middle 

 femora, and the hind femora except the tip, black. Length of body, 

 10'""' ; of the wings, L0.5'"'". 



Third joint of the antenute a little longer than the other two together. 

 Eyes pilose. Lateral stripes of the thorax interrupted Scutellum 

 wholly yellow. Abdomen globose, fasciae of moderate width, moder- 

 ately arcuate, narrowly interrupted, usually separated from the lateral 

 margins, and from the ])Osterior margin, sometimes, by the luteous 

 spot in the posterior angles, joined with them; posterior margin of 

 the first segment with a narrow yellow baud, or without it ; posterior 

 bands of the remaining segments of moderate width, the last dilated 

 into a triangular spot, separated from the fascia by a black, inverted 

 V-shaped spot. Last three segments of the venter each with a yellow 

 fascia on the posterior margin. Legs yellow ; base of the front and 



