224 BULLETIN 31, U]i.'ITED STATES Nifl'IONAL MUSEUM. 



secoud se<;meiit on the front i)arr,an(] a band beyond the middle of" about 

 the same width, somewhat angnhited in front in the middle; third seg- 

 ment similar, except the front border may be (inite narrow and the 

 cross-band sub interrn]ite<l ; fourth Nejiinent in male wholly jnetallic, 

 concealing the hyiK)i>>giiim, in the female with a very narrow front bor- 

 der and narrow interrupted cross-band ; the black bands aie attenuated 

 on the sides, not quite i caching the lateral margins. Legs yellow; 

 femora rathe'" stout, the h ind i)aii' moderately thickened ; front and mid- 

 dle pairs mostly brownish or black, sometimes ])revailing yellow, black- 

 ish above, hind femora varying from a blackish ring near the base to 

 almost wholly black, below with short black bristly hairs near the end ; 

 last three joints of the tarsi black. Wings smoky hyaline, stigma yel- 

 lowish brown. 



Twelve specimens, Mount Hood, Oregon, and Washington Territory 

 (H. K. Morrison, Professor Comstock). 



XYLOTA.* 



Xylota Meigeu, Syst. Beschr. iii, 211, IS'i'i. 

 Heliophilus Meigen, Illiger's Mag., ii, '273, 1803. 

 Micraptoma Westwood, Introduction to Class, of Insects, i. 



Medium to large sized species, slender, the abdomen more or less red, 

 yellow, or metallic. Head hemispherical. Antennae situated on a 

 more or less ])rominent conical projection, flrst two joints short, the 

 third rather large, oval or round, with a basal, bare arista. Face in 

 ])rofile concave, without tubercle, transversely arched or rarely carinate, 

 oral margin m front projecting, but not extending as far forward as 

 the base of the anteume. Eyes bare, contiguous in the male; front in 

 female narrowed above. Thorax large; scutellam thinned on its bordei . 

 if the color of the thoracic dorsum. Abdomen not wider than the thorax, 

 twice or thrice as long, somewhat flattened and usually witli nearly 

 l)arallel sides. Legs stout; the hind femora elongated and more or less 

 thickened, below with a row of short spines, tiot arcuated; hind (;oxje 

 in the male fiecinently with a. spinous tubercle below; hind tibiie aicuate, 

 often teriiiiiiating in a s])ur. Wings when at rest usually folded ovei- 

 each other; maiginal cell open, third vein straight or gently curved, 

 anterior cross vein at or beyond the middle of the discal cell, more or 

 less oblique„ 



TABLE OF SPECIES. 



1. — Legs wholly Itlack ; hind foiiiora iiuu-li tliickoiied 2 



Legs not wholly black • .... 3 



2.— Wholly black ; wings black chalybea 



Abdomen chiefly red; the second segment with a basal black triangle; wings 

 nearly hyaline pigi'^- 



*^v\ov, wood. 



