THE CANADIAN ENTOMOLOGIST 341 



dividing the former by the latter. This I did with five specimens 

 of each sex: the males gave 2.63; 2.70; 2.75; 2.81; and 2.20,— 

 average 2.62; — while the females gave 2.75; 3.50; 3.50; 3.00; and 

 4.00,— average 3.35. 



Length 1.5 to 1.7 mm. 



Seventy-five specimens, both sexes: 68 from Treesbank, 

 Man., (Criddle); 2 Moscow, -Idaho, determined by Becker as 

 DicrcBus ingratus; 1 Potlatch, Idaho; 1 Emigration Canyon, Utah, 

 back of Salt Lake City, about 7,000 feet; 3 Powderville, Mont., 

 (R. R. Parker). The- Potlatch specimen is dated June 20, the 

 rest all in July. 



Elachiptera planicollis, Beck. 



Becker, Mon. Chlorop., IV, 114, 1912 (Oscinella).— Collins, 

 Ida. (By mistake Collins, Texas). 



The type is in Professor Melander's collection, and until I 

 saw it in 1916 I failed to identify the species, having it in my col- 

 lection as Elachiptera n. sp. It is in reality very closely allied to 

 the abundant Elachiptera longula, having the same elongated 

 shape, diagonal eye, flattened thorax and scutellum; but differing 

 in having the arista not thickened and all the femora black. The 

 colour as in longula is opaque, but inclines more to plumbeous. 

 As far as the aristal character is concerned, there is a little varia- 

 tion in the thickening in both species, so I have specimens running 

 together in this respect. Becker placed longula in Melanochseta, 

 in which he also placed aliena, a species having a plain arista like 

 that of planicollis; but at the same time he admitted that there 

 was no natural line of division between Elachiptera and Me- 

 lanochseta, either in the European or North American fauna. 



My specimens of planicollis are the following: 26 from Trees- 

 bank and Aweme, Manitoba, collected by Mr. Criddle from June 

 to September; 4 from Chatcolet, Idaho, August 15, collected by 

 Professor Melander; a;nd 1 from Waubamic, Ont., near Parry 

 Sound, collected by H. A. Parish. 



Oscinis criddlei, n. sp. (Fig. 21.) 

 •A black species with the fore and middle tibiae and all the 

 tarsi wholly yellow, and the third antennal joint subangulated 

 above at apex. 



