HOW TO KNOW THE BUTTERFLIES 



This is a tropical species that invades the United States in 

 Texas, and occasionally flies northward to the Mississippi 

 Valley. 



The Cloudless Sulphur 

 Callidryas eubule (Cal-lid'ry-as eu-bu'le) 

 Plate XVI, Fig. 3, 4 



This large butterfly expands two and one-half inches. The 

 wings above are of uniform bright canary-yellow. In the male 

 they are without spots, except frequently an inconspicuous 

 brown dot at the tip of each vein, and a lilac-brown edging 

 of the costal border. In the female there is a discal dot on 

 fore wings and a marginal row of brown spots at the ends of 

 tire veins. 



Caterpillar. — Length, one and two-thirds inches ; color, 

 pale yellowish green with a yellow band along each side. The 

 segments are dotted with black in crosswise rows. 



Food-plants. — Cassia and other legumes. 



Thus says that classic book, Smith and Abbot 

 (1797), opposite the page whereon the cloudless 

 sulphur is depicted in all its canary-colored glory 

 near a flowering branch of cassia : " It is curious 

 to obferve the conformity of colours between the 

 flowers of this plant and the fly bred upon it. We 

 Ifiall have occafion to note other inftances of the 

 fame kind, and there are many of them through- 

 out nature. In fomc cafes thofe refemblances 

 feem to anfwer the purpofe of protection ; as 



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