272 BUTTERFLIES 



that looks like a Swallowtail. Its hind wings project 

 backward as long, broad tails in a way that marks the in- 

 sect at once as different from anything else. It expands 

 nearly two inches and when the front wings are spread at 

 right angles, the distance from the apex of the front wing 

 to the end of the tail of the hind wing just about equals 

 the expanse. The general color is dark brown, with about 

 eight more or less rectangular silvery spots on each front 

 wing. 



This is distinctly a tropical species which is common 

 along the Gulf Coast from Mexico to Florida. It ranges 

 north along the Atlantic Coast to New York City and 

 even to Connecticut. In the South Atlantic states it is 

 common, but toward the northern limits of its range it is 

 very rare. 



In the West Indies this butterfly is very common and 

 has been observed to rest with its wings vertical, the 

 front ones held far back between the hind ones and the 

 tails of the latter held at right angles to the plane of the 

 wings. Apparently, this curious fact was first noted by 

 Dr. G. B. Longstaff. Of course in museum specimens 

 the wings have been flattened into the same plane during 

 the process of drying, so that this peculiarity would not 

 be noticed. 



JuvenaPs Dusky-wing 



Thanaos juvenalis 



There are few trees which have so interesting a set of 

 insects attacking them as does the oak. It would be a 

 simple matter to find abundant material for a large vol- 

 ume by making a study of the life-histories of the various 



