328 THE STUDY OF INSECTS. 



wings yellow (Fig. 403). A variety of this species occurs in 

 California in which the lighter parts of the wings are pinkish 

 instead of yellow. These moths occur in stony places, 

 where the larvae feed on lichens growing on rocks. 



In the extreme southern part of our country and in the 

 regions south of that, there occur highly specialized mem- 

 bers of this family, in which the hind wings are greatly re- 

 duced in size, and the veins of the hind wings coalesce to a 

 remarkable degree. In some of these forms the discal por- 

 tion of the wings bears but few if any scales. Cosmosoma 

 auge (Cos-mo-so'ma au'ge) from Florida (Fig. 400) will serve 

 as an example of these. In this species the body and legs are 

 bright red, with the head, end of abdomen, and a dorsal band 

 blue-black ; the veins and borders of the wings are also black. 



Family THYRIDID.E (Thy-rid'i-dae). 



The Window-winged Moths. 



These little moths can be easily recognized by the presence 

 of curious white or yellowish translucent spots upon the 

 wings ; it is these spots that suggests the name Window- 

 winged Moths for the family. 



In this family the antennae are either strictly filiform or 

 slightly thickened in the middle ; 

 the ocelli are wanting ; the palpi 

 project horizontally, and are 

 somewhat longer than the head ; 

 and the maxillae are strongly 

 developed. The venation of the 

 wings differs from that of all 

 other families of moths, in that 

 all five branches of radius of the 

 fore wings are preserved and arise 

 from the discal cell (Fig. 404).* 

 A similar type of venation is 



FIG. 404. Wings of Thy 



* In a single genus of the Pyromorphids, Triprocris (p. 227, Fig. 268), 

 all the branches of radius arise from the discal cell. 



