PLATE XVIII. 



Fig. 1. — Chionaspis ortholohis Comstock, on Salix sp. Anal plate of fe- 

 male, showing somewhat irregular position of dorsal glands. 



Fig. 2. — Chionaspis ortholohis Comstock, on cottonwood, Populus sp. Anal 

 plate of female, illustrating variations in second and third lobes. The dorsal 

 glands, second and third rows, in this figure, as in figure 1, are shown beneath 

 the circumgenital glands. These are frequently located laterad of circumgenital 

 glands. 



