26 4 



THE STUDY OF INSECTS. 



The characteristic features in the structure of the wings 

 are the following (Fig. 311): the fore wings have a single 



anal vein, the hind 

 wings two ; in both 

 wings cubitus is 

 apparently three- 

 branched ; and the 

 subcosta of the hind 

 wings does not make 

 a sharp bend into 

 the humeral angle 

 as it does in the 

 Geometridae (Fig. 

 323). In some 

 forms the basal part 

 of vein V is more or 

 less distinctly pre- 

 served ; and in some 

 an accessory cell is 

 present. 



FIG. 311. Wings of Notodonta stragula. The larvae feed 



upon the leaves of shrubs and trees. Our most common 

 species live exposed ; but some species live in folded 

 leaves. They are either naked or thinly clothed with 

 hairs. Many species have only four well-developed pro- 

 legs, the anal pair being rudimentary, or transformed into 

 elongated spikes. Some species are hump-backed; and 

 spines or fleshy tubercles are often present. The trans- 

 formations occur in slight cocoons or in the ground. 



The family is a large one, more than one hundred species 

 occurring in the United States. The following are some of 

 the more common species : 



The Handmaid Moths, Datana (Da-ta'na). Among the 

 more common representatives of the Notodontidae are cer- 

 tain brown moths that have the fore wings crossed with 

 bars of a different shade (Fig. 312), and that bear on the 



