Explanation of Plate 8. 



Portion of the edge of the pygidium of different species. 



Fig. i. Chionaspis dysoxyli. 



Fig. 2. Chionaspis ortholobis. 



Fig. 3. CJiionaspis americana. 



Fig. 4. Second lobe of Chionaspis americana showing variation. 



F i g. 5 . Ch ionaspis caryae. 



Fig. 6. Chionaspis furfura. 



Fig. 7. Chionaspis longiloba. 



Fig. 8. Chionaspis corni. 



Fig. 9. Chionaspis stanotopJiri. 



