22 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 82 



PSEN (MIMUMESA) MELLIPES Say 



Plate 1, Figure 10 



Psen mellipes Say, Boston Journ. Nat. Hist., vol. 1, p. 369, 1837. 



This species and the next one are distinguished from the four 

 that have preceded them in this paper by the yellow underside of the 

 antennal flagellum, which is least conspicuous in the male of cana- 

 densis. The very noticeable distinction between the black apical 

 segment of the flagellum and the preceding segments in the male is 

 a reliable distinguishing character for the species in that sex, and 

 the underside of the flagellum in the female is more broadly yellow 

 than in any other species of the subgenus except johnsoni, but in the 

 latter the yellow color is confined to the basal half of the flagellum. 

 The tibiae in the female are not entirely yellow, even the fore pair 

 being sometimes partly darkened, and the hind pair are usually 

 mostly black. The peculiar swellings of the intermediate segments 

 of the antennal flagellum in the male readily distinguish the species 

 from canadensis, and the most distinctly elevated of these are much 

 darker than the remainder of the segments upon which they are 

 situated. 



Length, 6-7.5 mm. 



Originally described from Indiana, and recorded from New York 

 by Fox. I have before me specimens from the following localities : 

 Colombus, Ohio, July 15, 1921 (A. E. Miller) ; Ames, Iowa, July 

 15, 1926, and August 4, 1927 (G. O. Hendrickson) ; 8 miles southeast 

 of Britt, Iowa, August 9, 1928 (G. O. Hendrickson) ; Funkstown, 

 Md., August 3, 1916, Cage 832 (P. R. Myers) ; Anacostia, D.C., 

 August 9, 1914 (W. D. Appel). 



PSEN (MIMUMESA) CANADENSIS, new species 



Male and female. — Similar in general characters to mellipes, 

 distinguished in the male by the color and structure of the antennal 

 flagellum and in the female by the slight but distinct emargination 

 of the central production of the clypeus, and the mucli darker 

 tibiae, which are usually all black. Both species have the petiole 

 of the abdomen with the central carina rather poorly developed 

 and the basal half of it with 2 or 3 irregular impressed lines, which 

 are largely waved. 



The pygidium in the females of both species is much broader than 

 in the niger group, being similar to that of clypeatus, the surface 

 covered with quite deep and closely placed piliferous punctures, so 

 that it appears entirely dull. This last is generally considered as 

 a group character, but other features appear to link the two spe- 

 cies with the present subgenus despite the lack of a well-defined 



