COLIAS IV. 



shortest reaching twentj-five days. These as well as their larvse were kept in a 

 warm room. 



The present species traverses a vast extent of territory, embracing all of the 

 United States west of the Mississippi River, besides a considerable area to the 

 east, and an undefined portion of British America as well as of Mexico. This 

 region covers 40° of longitude and upwards of 30° of latitude, and presents 

 every variety of surface and climate. To the southward, the summer is pro- 

 longed and the winter short and mild ; at the north the reverse of this is the 

 fact, but on the plains of Texas or the prairies of Illinois, on the elevated pla- 

 teaus of Colorado, or in the secluded valleys throughout the Rocky Mountains, 

 and over the Sierras to the Pacific, the species is equally at home and is every- 

 where abundant. It occupies with PMlodice the whole of the United States 

 and much of British America, and like that species, which it resembles in every 

 respect but in color, it is subject to great and extreme variation, there being no 

 feature whether of size or ornamentation that is not unstable. In Vol. I., I gave 

 such history of Eurytheme and Keewcvjdm as I was then able, but since those 

 brief relations were printed, and indeed, within the past three years, by repeated 

 breeding from the egg, together with careful and extended observations in the 

 field, in many localities, it is rendered certain that we are dealing with a bi- 

 formed and triformed species, and that Ariadne, Keewaydin, and Eurytheme are 

 but so many seasonal manifestations of it. Also, that in some districts the 

 species is not seasonally polymorphic, but is simply a variable one, like Philo- 

 dice: 



This Colias is not found in West Virginia, nor have I ever seen it alive, but I 

 have been aided by several friends in the eflbrt to learn its full history : by Mr. 

 Dodge, of Glencoe, Nebraska, who has raised several lots of larvie from summer 

 females, and sent me the resulting butterflies ; by Mr. Bean, of Galena, Illinois, 

 from whom I received larvae of the last brood of butterflies of the year, and so 

 was enabled myself to follow the several changes. Mr. Bean has also given me 

 full notes of all the stages of larvae raised by him at same time, and of summer 

 larvae besides, and a tabulated statement showing the forms of this species taken 

 by him in the field, with dates of capture. Mr. Worthington, at Chicago, has 

 sent me a similar table. Mr. Mead has furnished notes from his experiences in 

 Colorado and California in 1871, and besides this, I had the opportunity of ex- 

 amining all the specimens collected by him. And Mr. Henry Edwards has sent 

 many examples and records of his captures and obsei'vations in California and 

 elsewhere on that coast. He has also published a valuable paper on the Coliades 

 in the Proceedings of the California Academy, Vol. VI., 1877, of which I have 

 availed myself. Finally, Mr. Boll, of Dallas, Texas, has sent a paper read by 



