SYNOPSIS OF NORTH AMERICAN SYRPHID^. 253 



specimens not infrequently is greyish, or even obsolete. A square spot 

 at the inner side of the humeri deep opaque black; in the middle of the 

 dorsum in front, a broad, faintly grayish, pollinose stripe. Scutellum 

 opaque at its base, broadly metallic shining green on its border ; pile 

 blackish. Abdomen oval, golden yellow and black, opaque ; first seg- 

 ment black ; second segment black with two yellow cross-bands, con- 

 nected oil the lateral margins, the first narrowly, the second very 

 broadly intetrupted; third segment with a median black cross-band, 

 dilated in the middle diamond shaped, sometimes cut off from an oval 

 spot on the sides, the first band interrupted by a linear si)ace ; fourth 

 and fifth segments with three small black spots each, the middle one 

 larger, on the fourth segment sometimes coalescent; margins of the 

 segments narrowly black. Legs reddish yellow ; front tibiae (except 

 the base) and their tarsi deep black ; front femora at their base, and 

 sometimes the other pairs below near the base, more or less black. 

 Wings brownish in front, nearly hyaline behind, the third vein beyond 

 the cross vein broadly hyaline along its sides. 



Eight specimens. One specimen from Pennsylvania (Keen) has the 

 first yellow cross- band of the abdomen more broadly interrupted than 

 the second, the yellow each side not reaching a third of the way across; 

 the base of all the femora are also more blackish. 



Temnostoraa venustum, n. sp. 



Temnosioma excentrica Osteu Sacken, Harris' Ins. Inj. to Vegetatiou, 3d. ed., p. 

 610; Cat. Dipt., p. 253, uote (female). 



Hahitat. — Massachusetts, Lake Superior (U. S.), New Hami^shire. 

 9 . Length, 15"""". Very closely allied to T. aequale, but differs in 

 having two yellow spots on the suture (like T. alternans) on each side. 

 The pile of the scutellum is black, the second abdominal segment lacks 

 the anterior cross-band, and the hind one is confined to the sides, the 

 lateral margins of the segment also being narrowl^^ yellow; both cross- 

 bands of the third segment are narrow, the anterior one of the fourth 

 segment also. The remaining ones are broader, and the black is inter- 

 rupted in the middle of the fourth and fifth. In my siugle specimen 

 the two hind femora are brown, the front one black, except the tip. 



One specimen, White Mountains, New Hampshire (S. Henshaw). 



Temnostoma aequale. 



Temnosioma aequalis Loew, Centur., v, 36. 

 Habitat. — British North America (Lw.), New England, Colorado! 

 5,9. 14™'". Head yellowish-white pollinose, vertex, median frontal 

 and facial stripe and cheeks shining black, vertical triangle black, be- 

 low pollinose. Antennae reddish or brownish. Thorax black, but little 

 shining, in front in the middle a little grayish ; humeri, the sutures, 

 supra-alar vittula, and an elongate spot on meso-pleura, yellowish gray. 

 Scutellum metallic shining, its base narrowly opaque ; pile yellowish. 

 Abdomen black, moderately shining, the segments, except the first. 



