1898.] 



ENTOMOLOGICAL NEWS. 



IC7 



golden-yellow, that of the geno-vertical plates from light brown to golden- 

 yellow, and that of the genae from reddish brown to golden-yellow; buccae 

 black (anterior half golden-yellow in some lights), their beard black; the 

 antenna has the second joint and the base of the third yellowish red, 

 almost of an orange color, the rest of the third has a light brown ground 

 color in the male (darker in the female) and the whole of the third is 

 thickly white pollinose. In the male the third antennal joint is decidedly 

 more slender than in americana. The thorax is rather longer in propor- 

 tion to its width than in americana; its chaetotaxy is alike in the two spe- 

 cies, except that elongata has a small anterior intra-alar macrochaeta and 

 both my female specimens have three anterior and three posterior achros- 

 tical macrochaetae (each of my males has two anterior achrosticals; one 

 has one, the other two posterior achrosticals). The abdomen in all my 

 specimens is green and has a slight, but distinct white pollinose coating, 

 much more than I have ever observed in americana; its hairs are coarser 

 and less numerous, and the lateral macrochaetae more appressed than in 

 americana; each abdominal segment is longer in proportion to its width 

 than in americana. The hypopygium is less densely hairy than in atneri- 

 ■cana, but its terminal hooks are of about the same size as in that species 

 (far smaller than in mortuorum). The long hair on the outer surface of 

 the fore and hind thighs is shorter and less dense than in americana. 



Two males and two females. One of the males and one of the 

 females are mounted on the same pin, whence I infer that they 







were taken in copula; their locality label says So. Dakota, Sep. 

 19th; I received them from Prof. J. M. Aldrich. One female 

 {also from Prof. Aldrich) bears label, Brookings, So. Dakota. 

 One male, from Prof. W. M. Wheeler, is labeled Torrey's Lake, 

 Wyoming. 



While most dipterists are aware that individual variations in 

 chaetotaxy occur, I do not think that any observations have been 



