THE TRIBE OF THE LARGER SKIPPERS 275 



be killed by freezing up with moisture. But the cater- 

 pillar is able to provide against these dangers. It has 

 apparently an abundant supply of liquid silk to secrete 

 from the silk glands in its head, so it lines its tubular tent 

 with a dense silken web that effectually excludes enemies 

 and moisture. It thus has on the outside of its nest the 

 thick oak leaf and on the inside a dense soft lining that 

 makes a most admirable winter protection. So it remains 

 here throughout the winter, the leaf commonly staying on 

 the tree until early spring. Then leaf, nest, and enclosed 

 caterpillar are likely to drop to the ground to remain until 

 spring arrives in earnest. Just what happens then seems 

 to be a bit doubtful. The caterpillar changes to a 

 chrysalis, but whether it first works its way out of its 

 winter nest and makes a new and less dense covering seems 

 not to be certainly known. Here is another good oppor- 

 tunity for some careful observations. 



At any rate, the caterpillar changes to a chrysalis, and 

 late in spring it changes again to an adult butterfly that 

 flits about on dusky wing for a few weeks before it 

 dies. 



The Sleepy Dusky-wing 



Thanaos hrizo 



The appearance of this butterfly both as to size and 

 marking is very similar to that of Juvenal's Dusky- wing 

 except that the white spots are not present on the front 

 wing of this species. The life-histories of the two species 

 as well as their distribution seem to be closely parallel. 

 The present butterflies are to be found early in summer in 



