1920] 



Fr acker: Lepidoptera 



171 



one of the four largest groups of ordinal rank in the animal 

 kingdom. 



The few exceptions to the phytophagous habit include such 

 very rare parasites as the Xylorictidae, and a few predators such 

 as one or two pyralids living on scale insects. Possibly the 

 clothes-moths and the wax moths, living on animal products, 

 might also be called carnivorous. None are parasites on living 

 vertebrates. 



TABLE IL MEANS OF PROTECTION. 



FORMS OF PROTECTION. 



In Table II the possible forms of protection against adverse 

 conditions are shown divided into "structural" and "external" 

 classes; the former depend on anatomical adaptation, the latter 

 on habit and mode of life. Here as in Table II, the division 



