168 
MOTHS AND BUTTERFLIES. 
sombre butterfly has a beauty of its own when perfect and carefully 
mounted. Then, too, the life-histories*of many of the kinds are still 
unknown, and a field for investigation lies open to the student. 
But two only of our more common species of this genus 
will be desci'ibed here. Thanaos brizo is very common in the 
eastern and middle states, being found as far west as the Rocky 
Mountains, and on warm sunny days in early spring may be found 
along roads and paths through the forests or the young growths of 
oak. It often alights on the ground or on low herbage. This insect 
is very sombre in coloring. The upper wings are dark blackish- 
brown, with two indistinct and ill-defined rows of dark bluish-gray 
Thanaos hrizo. 
oval spots surrounded by black. The lower wings are brown, with 
two faint rows of yellowish-brown spots near the lower margin. 
Underneath, both wings have two rows of yellowish spots. 
Thanaos persius. 
Thanaos persius is a common insect and widely distributed over 
the continent. The upper wings are bluish-gray, with three irregular 
