154 The Ohio Journal of Science [Vol. XIX, No. 2, 



Dimmock, (M. C. Z.) ; Morrison, (U. S. N. M.) ; New Hampshire, 

 Ottolengui, (U. S. N. M.); Maine, (U. S. N. M.); Isle Royale, 

 Mich., July 26, 1905, (Hine) ; Dickinson County, Mich., July 

 6, 1909, Michigan Biological Survey, (Hine) ; Heyden, Ontario, 

 July 31, 1906, E. B. Williamson, (Hine); Sault Ste. Marie, 

 Ont., (Hine); Creede, Colo., Aug., 1914, 8844 feet elevation, 

 S. J. Hunter, (Hine); Tolland, Colo., Aug. 15-16, 1917, E. C. 

 Jackson, (Biol. Survey); Washington, Brodie, (U. S. N. M.); 

 Kaslo, B. C, June 12, 18, R. P. Currie, July 11, 1903, A. N. 

 Caudell, (U. S. N. M.). 



There is considerable resemblance between the females of 

 this species and those of Dasyllis fernaldi Back. The latter 

 may be distinguished however by the erect position of pile on 

 posterior part of thorax, the greater abundance and entirely 

 yellow color of pleural pile and more copious yellow hair on 

 tibiae. Males of this species of Dasyllis may be recognized by 

 the characteristic form of genital forceps, (Fig. 24). 



Laphria ferox Williston. 



Laphria ferox Williston, S. W. On the North American Asilidae (Dasypo- 

 goninae, Laphrinae), with a new genus of Syrphidae. Trans. Am. Ent. Soc. 11, Dec, 

 1883, pp. 29-30 (Washington Territory). 



This species was originally characterized from females only 

 and knowledge of males now calls for some alteration of the 

 description. 



Vestiture black, except for beard, coxal hairs, part of the hairs on 

 posterior part of thorax, all of which vary from whitish to golden. 

 Pubescence of abdomen yellow to reddish golden, more dense on hind 

 margins of segments and upon posterior and anterior segments, except 

 in males in which the pale pubescence is confined to first four segments 

 and posterior margins of others, the remaining hair being black. Wings 

 blackish hyaline to smoky. The male genitalia of this species bear the 

 most remarkable appendage of any of the genus seen by the writer. 

 This is a single, median, brush-like process of each forceps which is 

 broad, about half as long as the process, oblique and fimbriate at apex. 

 It seems distinctly a lamella composed of coalesced bristles, which are 

 separate toward the apex, but solidly fused near base. (Fig. 5). 

 Length, 15-22 mm. 



Specimens examined: Grouse Mt., Vancouver, B. C, 

 July 1, 1904, (Hine); Victoria, B. C, July 20, 1902, (Hine); 

 Hoquiam, Wash., Sept. 4, 1903, H. E. Burke, Homotype, 

 (U. S. N. M.); Evaro, Mont., May 4, 1913, L. O. Swartz, 



(U. S. N. M.). 



