1924] 
New Caly pirate Diptera from New England 
199 
third of mesonotum much broader, that on line of intra-alar 
bristles more elongate, and the apex of sciitellum more broadly 
gray. 
Structurally this species differs from all others of the genus 
in having the antennae separated at bases by a very noticeable 
rounded carina which is distinctly shining on upper part, and 
the epistome is much more produced, the anterior margin being 
almost in line with anterior margin of third antennal segment. 
Eyes subnude; arista almost bare. Hind femur usually with but 
two posteroventral bristles, one at base and the other near middle; 
posterodorsal bristle on hind tibia rather short. 
Length, 3-4 mm. 
Type, Buttonwoods, R. I., July 25, 1911. Paratype, Tiver- 
ton, R. I., July 31; Woodbury, N. J., June 27, 1896; Eastham, 
Mass., June 21, 1908 (C. W. Johnson); Potomac Run, Va., May 
30, 1916, on Chrysanthemum leucanthemum; Chesapeake Beach, 
Md., September 19, 1915; Beltsville, Md., August 8, 1915 (W. 
L. McAtee) ; Denton, Texas, April 27 (C. R. Jones). 
Stein has placed micropteryx Thomson, anthracina Bigot, 
and monticola Bigot as synonyms of alhicincta Fallen and sug- 
gests the same relationship for bidentata Malloch. I have yet to 
see an authentic North American specimen of albicintca, my 
records and most if not all of those of Stein having reference to 
micropteryx Thomson, judging from what I know of the dis- 
tribution of this species, which was described from California. 
It is highly probable that both the Bigot species are synonyms 
of this species also, but only an examination of the types will 
determine this. I have again examined the type of bidentata 
and consider that it is distinct from the other species, having a 
larger velvety brownish black frontal triangle, the orbits with 
denser bristles, the profile of the head different, and the dorsum 
of thorax and abdomen deep black, with only a very short 
whitish triangle on each side of the median line of each abdominal 
tergite. We have thus apparently three distinct species in 
North America, and from an examination of material which I 
was permitted to make in the U. S. National Museum by Dr. 
Aldrich I believe we have probably two others in South America 
and Mexico. 
