AMERICAN HYMENOPTKRA. 179 



Classification of Bees of the Genus BOMBOHELECTA. 



BY H. L. VTERECK. 



This synopsis is the result of a study of all material available at 

 the Academy of Natural Sciences, Philadelphia, comprising all the 

 described species of North America. 



Females. 



Pygidial area cuneiform, fiat 1. 



Pygidial area with the sides parallel or nearly, usually elevated along the mid- 

 dle 2. 



1. First joint of fiagellum distinctly longer than the second ; first abdominal seg- 



ment with pale pubescence thoracica Cress. 



First joint of fiagellum about equal to the second ; first abdominal segment 

 black zygos n. sp. 



2. Ten mm. long; abdomen maculated with white bars of appressed pubescence. 



arizonica Ckll. 

 Larger, 12 mm. and over, abdomen if spotted not distinctly 3. 



3. Abdomen all black, excepting thin bands of light brown appressed pubescence. 



larreae Ckll. 

 Abdomen with pale long pubesceuce on first segment 4. 



4. Dorsulum with a band of black hair extending from one wing to the other. 



separata Cress. 

 Pubescence of dorsulum coucolorous 5. 



5. Pubescence of dorsulum pale ochraceous pacifica Cress. 



Pubescence of dorsulum orange fulvous I u I \ i<!;i 



Males. 



First joint of fiagellum distinctly longer than the second 1. 



First joint of fiagellum distinctly shorter than the second 3. 



1. Joints of fiagellum remarkably thickened; second joint broader than long. 



All except dorsulum with black pubescence azygos n. sp. 



Joints of fiagellum slender; second joint longer than broad 2. 



2. Pubescence ranging from almost white to pale ochraceous and yellow ochra- 



ceous pacifiea Cress. 



3. Face with white pubescence ; abdomen with bands of white appressed pubes- 



ceuce alfredi Ckll. 



Face with black pubescence; abdomen all black edwardsii Cress. 



Bombomelecta zygos n. sp. 



9- — Length 14 mm. — Head covered with indistinct punctures, hidden in 

 greater part by the long black hair which occupies all of the head except the 

 margin of the occipital region. The ocelli placed on an imaginary straight line, 

 the distance between the lateral ones about, equal to the distance between theni 

 and the nearest eye margin. A distinct thin keel medially placed between the 

 insertion of the antennas, continued as a raised line and then a streak up to the 



TRANS. AM. ENT. SOC., XXIX. MAY, 1903. 



