THE SWALLOW-TAILS 



The Zebra Swallow-tail 



Iphicttdes ajax (Iph-i-cli'des a'jax) 



Plate V, Fig. i, 2 



This butterfly differs from all other swallow-tails found in 

 the eastern half of the United States in having the wings 

 crossed by several bands of greenish white. This is one of 

 the most interesting of our butterflies, as it occurs under three 

 distinct forms, two of which were considered for a long time 

 distinct species. Without taking into account the more 

 minute differences these forms can be separated as follows : 



(1) The Early-spring Form, Iphicttdes ajax marcellus (mar- 

 cel'lus). — This form expands from two and six-tenths inches 

 to two and eight-tenths inches ; and the tails of the hind 

 wings are about six-tenths inch in length and tipped with 

 white. (Plate V, Fig. 1.) This form was described by Mr. 

 Edwards under the name wahhii and is still often incorrectly 

 so called. 



(2) The Late-spring Form, Iphicttdes ajax telamonides (tel- 

 a-mon'i-des). — This form is a little larger than marcellus and 

 has tails nearly one-third longer ; these tails are bordered with 

 white on each side of the distal half or two-thirds of their 

 length. 



(3) The Summer Form, IphicUdes ajax ajax. — The summer 

 form is still larger, expanding" from three and two-tenths 

 inches to three and one-half inches, and has tails nearly two- 

 thirds longer than the early-spring form. (Plate V, Fig. 2.) 

 Owing to an unfortunate error this form is often called 

 marcellus. 



The life-history of this species has been carefully worked 

 out by Mr. W. H. Edwards. He has shown that there are 



49 



