158 ENTOMOLOGY 
206) ; while male Coccidze have what is essentially a complete 
metamorphosis. In fact, the various kinds of metamorphosis 
Cicada tibicen. A, imago emerging from nymphal skin; B, the cast skin; 
C, imago. Natural size. 
grade into one another in such a way as to make their classifi- 
cation to some extent arbitrary and inadequate. 
