Vol. XI] COLE AND LOVETT—UST OF OREGON DIPTERA 275 



438. Chrysotoxum ypsilon Will. 



Mary's Peak, VII-14 (Bridwell) ; Lakeview, VIII-18 

 (Thompson). 



439. Chrysogaster bellula Will. 

 Mt. Jefferson, VIII (Bridwell). 



440. Chrysogaster lata Loew 

 Williston records from Oregon. 



441. Chrysogaster parva Shannon 



Hood River, V-15 to VI-6 (Cole). 1916, Proc. Ent. Soc. 

 Wash., XVIII, p. 104. 



442. Chrysogaster pulchella Will. 

 Hood River, VI- 17 (Cole). 



443. Chrysogaster sinuosa Bigot 



Hood River, VI-3 (Cole) ; Forest Grove, V-ll (Lovett). 



444. Chrysogaster stigmata Will. 

 Pamelia Lake, VII-24 (Bridwell) ; Hood River, VI-3 and 

 Forest Grove, IV- 12 (Cole). 



445. Pipiza 20 femoralis Loew 

 Hood River, VII-5 (Cole). 



446. Pipiza macrofemoralis Curran MS. 

 Hood River, VI-8 (Cole). 



20 The group Pipizini is a difficult one, individuals varying considerably, 

 having few outstanding characters sufficiently constant to be of service in 

 establishing genera. Particularly in the females the characters for differen- 

 tiation are more imaginary than real. In collecting where material in this 

 group is plentiful, it is frequently possible to obtain individual females, which 

 might provisionally be placed in each of the four genera, associating with 

 males specifically of one form. It is our belief that a closer study will show 

 this group to be in a transitional stage because of changes in food habits 

 of the larvae; the adults still mating more or less indiscriminately. 



Mr. C. Howard Curran of Ontario, Canada, who has undertaken the very 

 laudable task of straightening out this group, has kindly determined our 

 Oregon material and his classification is used in cataloguing these forms. 

 Mr. Curran's paper will appear in the succeeding number of these Proceedings. 



