THE CANADIAN ENTOMOLOGIST 55 



our region for its pollen, undoubtedly one of the Leguminosae, and 

 that through the gradual disappearance of that plant from our 

 immediate surroundings, the bee was forced to turn its attention 

 to some other suitable plant. A number of prairie plants still 

 inhabiting this particular area 30 or 40 years ago have been driven 

 out by the change of conditions due to the activity of man; other 

 species have invaded the area, and among these the white melilot 

 has been quite successful. 



P. maculipennis was described from the female sex; a descrip- 

 tion of the male is given herewith. 



Male. — Length 5-6 mm. Differs from the female as follows: 

 Flagellum conspicuously light yellow underneath, labrum and face 

 entirely yellow; this colour extends for a short distance above the 

 antennae, and runs obliquely up along the anterior orbits. A yellow 

 stripe along the posterior orbits, narrow above, and widening out 

 abruptly below. In addition to the yellow marks on tubercles, 

 tegulae and collar, there is a large yellow spot on the prosternum, 

 a smaller one on the mesosternum, and one on the metapleura; in 

 the smaller specimens these markings are poorly developed. In 

 the larger specimens two yellow interrupted abdominal cross-bands 

 on segments 5 and 6, besides those on segments 2 to 4. Front and 

 middle legs yellow, black only on posterior surfaces of femora and 

 tibiae. Hind legs black with a broad yellow band anteriorly on 

 the femur, and a narrow one on the tibia. Knees yellow. The 

 black spot in the stigma is very conspicuous, rather more so than 

 in the female. 



Four specimens taken June 29, 1913, in the type locality near 

 Milwaukee, Wis., flying around the flowers of the white melilot 

 (Melilotus alba Desv.) in search of the females. 



P. citrinella Graenicher. This species, a visitor of the flowers 

 of a leguminous plant. Petalo sternum villosum Nutt. is known 

 from two localities in Wisconsin: North Hudson, St. Croix Co. 

 (type locality), and Prescott, Pierce Co., about 15 miles south of 

 North Hudson. Last year it was reported by Mr. J. C. Crawford 

 (loc. cit.) from Medicine Hat, Alberta, Canada. 



It belongs to a group of yellow Perditas, and, as has been 

 pointed out in the description of the species, it stands in exceedingly 

 close relationship to two western species. One of these (perpallida 



