LEPIDOPTERA. 293 



the basal third of the wing, two black spots on the outer 

 half of the costa, a black spot at the inner angle, and a row 

 of black points on the outer margin. There is a variety 

 which lacks the black band and the four black spots. The 

 larva of this species has been found on red oak ; it is of a 

 rich yellow-brown, mottled with fine dark lines, and lives in 

 a case made by fastening leaves together. It makes a slight 

 cocoon late in September; the adult emerges in June. 



Family NOCTUID^E (Noc-tu'i-dae). 

 The Owlet-moths or Noctnids (Noc'tii-ids). 



This is the largest of all of the families of the Lepidop- 

 tera ; more than eighteen hundred species are now known to 

 occur in America north of Mexico. The great majority of 

 the moths that fly into our houses at night, attracted by 

 lights, are members of this family. 



The nocturnal habits of these insects, and the fact that 

 often when they are in obscurity their eyes shine brightly, 

 have suggested the name of the typical genus {Noctua, from 

 the Latin for owl), as well as the popular name Owlet-moths, 

 by which they are known. Similar popular names have 

 been given to them in several other languages, 



Although there is almost no question regarding the lim- 

 its of this family, as yet no structural character has been 

 found by which they can be distinguished from certain other 

 moths. Neither is there a general uniformity of appearance 

 which we can use for this purpose, as the family includes 

 great variations in size, form, and coloring. But most of the 

 species are dull-colored moths of medium size. 



The greatest difficulty arises in attempting to separate 

 this family from the three following. Of these the first two 

 (Pericopidae and Agaristidae) differ in their highly contrast- 

 ing colors, as pointed out in the analytical table (p. 212, 

 N and NN). In the third of these families (Lymantriidae) 

 the species have pectinate antennae and do not have ocelli. 



