A}!T. 9 FLIES OF THE FAMILY SYRPHIDAE SHANNON 29 



with a pair of yellow lunules which do not extend to the sides of the 

 abdomen; hind margins of fourth and fifth tergites yellow, the 

 fifth with a pair of small yellowish spots on anterior margin ; wings 

 glassy, almost entirely devoid of villosity; squamae whitish, disk 

 of lower one bare. Length 13 mm. ; wing 11 mm. 



/S. pyrastri differs in having the abdomen broader, and the abdom- 

 inal spots larger and more arcuate. 



The description of inelanostoma states that the sides of the thorax 

 are yellow. In the present species the sides are faintly yellow; 

 otherwise the description fits the species before me. 



Three males, eight females. Santiago, October 9, 1921 (A. Faz). 



Chile: Santiago, Valparaiso (A. Faz). 



Maipu, February 20, 1906 (F. V. Ibarro). 

 Southern Chile (M. J. Rivera). 

 Locality? (E. C. Reed). 



SCAEVA OCCIDENTALIS, new species 



Female. — Closely allied to inelanostoma., but differs in having the 

 front and face narrower; facial pile entirely pale; scutellum entirely 

 yellowish; hind femur less extensively black, almost half of the 

 apical half yellowish; tarsi more yellowish; the yellow abdoYninal 

 spots distinctly larger and less arcuate, the black separating the 

 spots in each pair narrower than the length of (front to back) the 

 spots (in melanostoma the black separating the spots much broader 

 than the length of the spots). Length 13 mm.; wing 10 mm. 



This species can hardly be that described as melanostom^a by Mac- 

 quart, as the yellow abdominal spots are distinctly larger and more 

 rotund than in pyrastri. 



One specimen. 



Type locality. — Santiago, Chile (A. Faz). 



Type.— Cut. No. 28749, U.S.N.M. 



Genus BACCHA Fabricius 



Baccha Fabricius, Syst. Antliat., 1805, p. 199. 



Six species of Baccha. have been described from Chile. Three 

 species are at hand, only one of which can be definitely connected 

 with one of the six already described. 



KEY TO THE CHILEAN SPECIES OF BACCHA AT HAND 



1. Alula well developed ; metasternum girdled with chitin ; wings hyaline 



with a distinct spot conopida Philippi. 



Alula absent; metasternum membranous behind; wings smoky 2 



2. Lower margin of eye contiguous with oral margin ; mesonotum entirely 



aeneous filiola, new species. 



Lower margin of eye distinctly separated from oral margin ; anterior lateral 

 mesonotal margin yellow felix, new species. 



