BUTTERFLIES OF MONTANA. 77 



same in chalcedon and cooperi. With all these well marked differences, 

 the two species look so much alike, that it would have been a long time 

 before cooperi would have been recognized as a distinct species, if it had 

 not been for the striking difference of its caterpillar, which was discovered 

 by Mr. Lorquin near Clear Lake on a species of Scrophularia. This cater- 

 pillar is much more elongated than that of chalcedon. It is nearly of 

 the shape and coloration of that of the European artemis, brimstone yel- 

 low, with a dorsal and a lateral black stripe. We were quite justified in 

 expecting from such a caterpillar something strikingly different from the 

 very common type of chalcedon. But to our surprise our chrysalids gave 

 us a series of crippled butterflies, which could scarcely be distinguished 

 from chalcedon. Since that time I have received a well developed speci- 

 men through the kindness of Baron Koels, wno caught it with several 

 other insects on an excursion to Mount Tamal Pais. 



It is pretty certain that cooperi will be found in many other localities, 

 as it is only its similarity to our most common vernal butterfly, the 

 chalcedon, that makes it escape our attention." 



(The above was kindly copied by M. E. Hyde, Asst. Sec. Calif. Acad. 

 Sci., from Behr's original description as given in the Proceedings for 

 1863-68, Vol. 3, p. 90.) 



Distribution Found in Washington, Vancouver's Island, and the Big 

 Horn Mountains, Montana. 



