AKT. 9 AMERICAN XYLOTINE SYEPHID-FLIES SHANNON 17 



arista shorter than width of face; legs sometimes brownish, never 

 yellow; pile on metasternum sparse; abdomen with first tergite 

 black; anterior border of second with black median triangular pro- 

 jection, remainder of abdomen red; metathoracic spiracle unusually 

 small, smaller than second antennal joint. Greene has figured the 

 puparium. 



Distribution. — A common species in Europe and North America,, 

 sometimes occurring in immense numbers. 



Type. — ^Location unknown. 



XYLOTOMIMA LIBO (Walker) 



Xyloia Ubo Walker. 



Xylota marginalis Williston. (Iu U. S. Nat. Mus.) 



Xylota liho Walker, Johnson, List of New England Diptera, 1925. 



Fairly large and robust species 10-13 mm. Mesonotum dark 

 brassy; abdomen purplish red; metasternum pilose; metathoracic 

 spiracle about the size of second antennal joint. A rather rare 

 species of northern and eastern North America. 



Distribution. — Originally des ribed from Nova Scotia (Walker). 

 Recorded from New Hampshire (Williston) ; Axton, New York 

 (Macgillivray and Houghton) ; Chapel Pond, Essex County, New 

 York, June 28. 1923 (M. D. Leonard) ; Duncun, British Columbia 

 (Osburn) ; Cincinnati, Ohio (Metcalf ) ; North Carolina (Metcalf ) ; 

 Maryland and Virginia (Banks, Greene, McAtee, Shannon). 



XYLOTOMIRLfl CURVIPES, variety SATANICA (Bigot) 



Xylota curmpes Loew, of authors. 



Xylota satanica Bigot. (Type in British Museum.) 



Professor Herve-Bazin has suggested to me the possibility that 

 the American form going under the name of cui'vljjes Loew is a dif- 

 ferent species from the European cwrvipes and gave me a specimen 

 for comparison. This specimen, a female, differs from the Ameri- 

 can form in having the fore and mid trochanters black (reddish 

 3^eliow in American female specimens) and the apex of the hind 

 femur two-fifths black, one-fourth black in American specimens. 

 The front is also slightly wider. A comparison of the male geni- 

 talia may prove the American form to be a distinct species. Mean- 

 while it is tentatively called a variety. 



Male. — Frontal triangle shining black, silver}^ poUinose on sides; 

 antennae brownish red, first joint darkest; arista brownish, a little 

 longer than width of face ; coxae black, remainder of four fore legs 

 reddish yellew ; hind legs black except basal three-fourths of femur 

 which is reddish yellow ; halteres yellow. Cerci unusually large and 

 apparently inflated; styles fairly stout, straight; basal lobe nearly 

 separated from rest of style by a deep narrow cleft ; beyond cleft the 

 .3042—2(3 3 



