AMERICAN HYMENOPTERA. 239 



Some Notes ou the Bee Genus ANDREW A. 



BY LAWRENCE BRUNER. 



Several years ago the writer undertook to determine and lable 

 the bees contained in the collection of insects belonging to the Uni- 

 versity of Nebraska. After some preliminary work in the way of 

 assorting and arranging the material at hand, and securing litera 

 ture with which to do the naming, it was found that the large num- 

 ber of the species belonging to the genus Andrena in its broad sense 

 could only be placed by the aid of some kind of synoptic key or 

 table. Not being able to find such an aid in our entomological 

 literature it was decided to construct one for the purpose. 



This being decided upon, it was soon ascertained that the various 

 authors who had established the already recognized and recorded 

 species had used different characters upon which to base their de- 

 scriptions. The use or choice of distinct characters by the various 

 authors when describing their species made it very difficult for the 

 writer when attempting to decide upon the principal features of the 

 proposed table in order to make it as nearly a natural one as possi- 

 ble. After several vain attempts at employing structural characters 

 for the separation of the main groups, at least, all efforts in this 

 direction ceased, and such secondary characters as the presence or 

 absence, length, abundance, color and arrangement of pubescence 

 were employed instead. This choice was made necessary because, 

 as stated above, the various authors when characterizing their new 

 species had overlooked many of the structural characters now used 

 in the limitation of forms. 



While nothing like perfection is claimed for the present table as 

 it now stands, it has been a great help to the writer in his attempts 

 at placing the hundred or more forms belonging to the collection 

 which he is working over. It is with this knowledge in mind that 

 the table is offered to others who may be interested in our Andrenid 

 bees. Later, after more of our species that are still undescribed 

 have been determined and characterized, and when both sexes of 

 some known species have been recognized, a new and better table 

 can be constructed. 



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



