o38 THE CANADIAN ENTOMOLOGIST. 



Fig. 2 is the inner side of an under membrane of a front wing. 



M 3 is the inner side of an upper membrane of a male hind wing, dis- 

 closing the inner side of the black sexual spot. 

 M 4 is the inner side of an upper membrane of a front wing. 

 M 5 is the inner side of the lower membrane of a female hind wing. 

 M 6 shows inner sides of both membranes of a winglet, united at the 



base. Its exact length is five-eighths of an inch. 

 M 7 gives a view of a perfect front winglet. The opposite one is 



incomplete. 

 1. 8 is the under surface of a hind winglet. The opposite one is the 



upper surface of another. Both imperfect. 

 I' 9-10 are the wings of one butterfly. Length, from base to apex, two 

 inches ; width at outer angle, one inch and a ([uarter. 

 The membranes at Fig. i were separated under water, and the 

 gummy fluid on their inner sides washed off clean. Those at Figs. 

 2, 3, 4 and 5 werr separated without the use of water, the expanding 

 fluid being allowed to dry on, producing the appearance of a thin coat of 

 varnish spread over the whole inner sides of the membranes. 



ON THE CLASSIFICATION O^ BEES. 



BY CHARLES ROBERTSON, CARLINVFLLE, ILLINOIS. 



During the last winter, in connection with the study of the local bees, 

 I had occasion to write out my views in regard to their classification, 

 basing my observations upon the recent Apidie catalogue of Delia Torre. 

 As the views then arrived at form a fair statement of my present opinions, 

 I venture to offer them in connection with the recent paper of Mr. Ash- 

 mead on the classification of the bees.* 



In the arrangement of these insects I attach the most importance to 

 the venation, since it is hardly subject to modifications connected with 

 changes of habit, and shows the least tendency to variation. In the 

 lower bees the first submarginal cell is about as long as the second and 

 third together, and its shortening may be regarded as a specialization. In 

 the more highly specialized venation the marginal cell is truncate or has 

 its apex more remote from the border of the wing. In a similar way a 

 small stigma may be regarded as a characteristic of the more highly 

 ^'Tinns. Am. lint. Sor.. \\'I\'. 49-100, 1899. 



