F. R. COLE 35 



A. L. Melander (104) has given some notes on tristis. The spe- 

 cies is relatively common in Idaho, according to Professor Aldrich. 

 The males sometimes have the third joint of the antennae sharp 

 at the apex, but as a rule it is blunt in both sexes. One female 

 from Marin County, California, has the abdomen brassy green; a 

 pair from Idaho are blue-black. There is a great inconstancy in 

 the juncture of the veins beyond the discal cell. In a California 

 specimen the vein separating off the second submarginal cell is 

 angulated near its base, and bears a short spur at the angulation; 

 while in the Idaho specimens the vein is evenly bisinuate, although 

 it bears a similarly placed short spur. The males have the second 

 submarginal cell petiolate at the base; in the female it is pointed 

 but nearly sessile, the very short petiole thickened; while out- 

 wardly the bounding veins of this cell diverge rather prominently, 

 not being parallel as in the female. 



A specimen from Stanford University (coll. Morrison) has the 

 venter metallic blue-green, the dorsum of the abdomen bluish 

 black with purplish reflections. The short yellow pile forms 

 bands on the abdomen both above and below. The head and 

 thorax are bluish green. Scutellum and thorax in front of it 

 purplish. Femora brownish black, knees and tibiae yellowish, 

 inner side of tibiae brownish. Tarsi and ends of tibiae light 

 brown. Knob of halteres yellowish, the stem brown. Proboscis 

 black, slightly longer than the body. Yellow hair on ej^es and 

 occiput; thorax and pleura yellow pilose. 



This species varies as much as smaragdinus. One female from 

 Muir Woods, California, has the vsecond submarginal cell petio- 

 late in one wing and not in the other. A male from Humboldt 

 County, California, has the proboscis shorter than the l^ody. In 

 this specimen the abdomen is bright metalKc purple and blue, 

 also the humeri. The scutellum is purple, the tibiae yellowish 

 brown, not darker on the inner side. A specimen from Kaslo, 

 British Columbia, is larger than the average and is shining green 

 with very little blue color. It is evidently a male but the an- 

 tennae are blunt. There is a stump of a vein on the second sub- 

 marginal at the base, the cell being petiolate. 



In the collection at the Oregon Agricultural College there are 

 twenty-eight specimens of E. tristis, taken at various places in 

 Oregon and at various times. Most of the specimens were taken 



TRANS. AM. ENT. SOC, XLV. 



