no. 2173. A REVISION OF THE BEMBICINE WASPS— PARKER. 89 



9-11. The apical segment is only slightly curved and when seen 

 from above is of uniform width from base to near the apex, which is 

 slightly rounded. The middle femora are distinctly dentate below 

 and the middle tibiae bear on their inner surface a distinct, but 

 not greatly compressed carina. The apical spur of the middle tibia 

 reaches to or beyond the middle point of the metatarsus. The second 

 sternite bears a median longitudinal process and the sixth a promi- 

 nent, elongated process that is flattened on its ventral surface in a 

 plane nearly parallel with the long axis of the body and is usually 

 bifurcate at the tip. The seventh bears a median prominent carina 

 and laterally near the base a pair of slight elevations. 



Female. — Black: Labrum, mandibles except apices, clypeus, lower 

 part of frons, anterior orbits, scape below, posterior orbits broader 

 below, broken spot on sides of prothorax, one or two small spots on 

 mesopleurae, fasciae on tergites 1-4 or 1-5, first narrowed medially 

 and rather widely interrupted, remainder strongly undulate and 

 narrowly interrupted medially, that on 5 sometimes broken or sup- 

 pressed, lateral spots on tergites 2-4 or 2-5, spot on anterior coxae 

 below, absent on some specimens, femora below more or less, tibiae 

 except broad stripe below, and tarsi, greenish white or greenish yellow, 

 the tibiae and tarsi having a rusty tinge. The sixth tergite is coarsely 

 and irregularly punctated with a tendency to become rugose at the 

 sides apically. 



Length. — 19-22 mm. 



The wings in both sexes are hyaline, veins brown. The head, 

 thorax, median segment and base of abdomen are covered with long, 

 dense pubescence, particularly well developed about the head, on the 

 median segment and base of abdomen. The pubescence on the basal 

 segments of the legs, dorsal surface of the thorax and the abdomen, 

 except the base, is shorter and less conspicuous. The scape is heavy 

 and stout, especially on the male. The flagellum is much lighter 

 below than above on the female, less evidently so on the male. The 

 apical spur on the middle tibia of the female is the same as on the 

 male. 



The extremes of the series show a wide variation in the color mark- 

 ings. This is especially true for the male. At one extreme the 

 abdomen is entirely black; at the other, tergites 1-5 each bears a 

 comparatively broad fascia interrupted medially, and the sixth a pair 

 of median spots. With reference to other macula tions the extremes 

 show a like divergence. At one extreme we find the sides of the tho- 

 rax and median segment showing only a small spot on the mesopleurae ; 

 at the other not only the thorax but even the sides of the median 

 segment show prominent maculations. Between these extremes, how- 

 ever, we find a well-graded series passing from one to the other. In 

 the female the divergence, though evident in the series, is not so great. 



