ART. ii6 WASPS OF SUBFAINIILY PSENINAE MALLOCH 31 



Flagellar segments 2 to 6 each with a slight linear elevation on one side 

 extending almost entire length of segment, which is but faintly visible in 

 profile (X 34) ; propodeum much more coarsely sculptured, rugoso-reticu- 

 late on at least the areas adjacent to enclosure ; petiole of abdomen rather 

 thick and not nearly so long as hind femur ; face at lower level of antennal 

 insertions a little wider than its length in center maculipes Fox 



PSEN (MIMESA) CRESSONI (Packard) 



Plate 1, Figures 13, 21 



Mimesa cressoni Packard, Proc. Ent. Soc. Philadelphia, vol. 6, p. 405, 1867. 



(Female.) 

 Mimesa denticulata Packard, Idem, p. 406. (Male.) 

 Psen cressoni Fox, Trans. Amer. Ent. Soc, vol. 25, p. 12, 1898. (Male and 



female.) 



This species is very readily distinguished from its allies by the 

 characters given in the key. The broadly yellowish testaceous under 

 side of the antennal flagellum in both sexes, with the distinct club- 

 bing, and the subangular median elevation on one side of the second 

 to fifth or sixth segments in the male, the very fine divergent striae 

 of the propodeum, particularly on the curve outside of the enclosure, 

 the long dorsally rounded parallel-sided petiole, and the sharply 

 carinate line on the inner side of each hind coxa combine to sep- 

 arate it from any other species of the subgenus. The entire sides of 

 the propodeum are almost smooth, at most granulose, and the width 

 of the face at lower level of the antennal insertions is not so great as 

 its length from there to the lower level of the center of clypeus. 

 This last character is distinctive, all the other species having the 

 width of the face at lower level of the antennal insertions about 

 equal to the central length. The head is also higher as compared with 

 its width in cressoni than in any other species, the two being about 

 equal, while in other species the width generally exceeds the height. 

 Hypopygium of male as in plate 1, figure 21. 



Length, 6-8.5 mm. 



Recorded from the following States : New Jersey, Delaware, Illi- 

 nois, Colorado, and Montana. Represented in material before from 

 Washington, D.C.; Falls Church, Va.; Beltsville, Md.; and from 

 Kansas, Nebraska, Iowa, Indiana, Washington, Idaho, Alabama, 

 New Hampshire, and Missouri. A series of rather small specimens 

 from Canada in the Baker collection. 



PSEN (MIMESA) CRESSONI ATRIVENTRIS. new variety 



This variety differs from the typical one in having the abdomen 

 black, with a slight reddish tinge on sides of the second segment. 



Type. — U.S.N.M. No. 44212, from Canada, no other data (no. 

 2068, Baker collection). 



