444 ENTOMOLOGICAL NEWS. [Dec., 'l6 



pomelas can be separated from alternata only by the color of 

 the pile on the pectus and venter. 



A $ , Elwyn, Pennsylvania (C. S. Welles) does not seem to 

 have the fore tibiae bristly, but they may have been broken off, 

 although I cannot find any trace of scars under high magnifica- 

 tion. 



Villa hypomelas. 



1840. Anthrax hypomelas Macquart, Dipt. Exot, ii, 3, I, 76, (pi. 

 xxi, f. i). 



Pile of face, pectus, abdominal segments 3 to 6 and venter black. Ab- 

 dominal segments black tomentose ; lateral margins all pilose. Pile of 

 segments i to 2 yellow or whitish; of apical segment white. Fore 

 tibiae setulose; claws minute. 



Described from North America. 



It is a question to me whether this is a distinct species. It 

 differs from males of alternata, var. nigropectus only in the 

 absence of pale tomentum and lateral white pile on segment 4. 

 These, however, are very faint on some specimens I have 

 placed under nigropectus. 



My limited series of this form does not contain any females, 

 and this suggests to me the possibility that I have them 

 among the females of nigropectus. 



Summary. 



The species lateralis and alternata, as I have recognized them, 

 may be separated as follows : 



Lateralis. Slender, with abdomen two or more times as 

 long as broad ; lateral margins of segments 3-7, furnished with 

 long cuneate scales, which are more or less mixed with pile ; 

 fore tibiae not bristly. Length. 7.0-12.0 mm. 



Alternata. Robust, with abdomen ovate, not more than 

 twice as long as broad ; lateral margins of segments 3-7 fur- 

 nished with long pile which is not intermixed with scales ; fore 

 tibiae bristly. Length. 12.0-16.0 mm. 



It is probable that these species in most collections are cor- 

 rectly determined as regards the typical and normally devel- 

 oped specimens. But the varieties and undeveloped specimens 

 will no doubt be found in confusion. 



