173 



yet reached the Rocky Mountains. It is advancing with cultivation, 

 and the spreading of the plant it feeds on, red clover, as I described in 

 the text of this species, But. N. A., Vol. II. These three differ from 

 their orange allies in color, all being yellow; but they differ among 

 themselves in the hue of yellow. The nearest to Eurytheme is Hageiiii, 

 the next is Philodice, and Eriphyle stands most remote. That some 

 Philodice are like some Eurytheme in all respects (in one or several 

 forms,) except color, is apparent to every one who is famdiar with the 

 two species. I spoke of it in my text of Eurytheme, Part V. Vol. II., 

 I'.ut. N. A., and Dr. Hagen quotes me approvingly; "he comes to the 

 conclusion that both species have exactly the same variations and only 

 differ in color." Also, "the larvae are scarct-ly, if at all, distinguish- 

 able in the earlier stages, and in the later, are often just as much alike.* 

 But in the later larval stages there is a conspicuous difference between 

 Eurytheme and Fhi/odice, the former having caterpillars, which after 

 the middle of the stage following the second moult, have developed a 

 series of sub-dorsal bands, as thus: on either side, on verge of dorsum, 

 a central white band, sometimes complete and continuous, sometimes 

 macular; over this, a red band, always macular; and under the white, 

 a series of ! lack dots, which may stand for a macular band. All lar- 

 vce do not show all these bands, s me not having the black, some 

 neither the black nor red, and some have no trace of any of them, and 

 so are not distinguishable from Philodice, which never has a sub-dorsal 

 band. These peculiarities are shown on my Plate. The two butterflies, 

 starting from the same point, have developed, one into an orange 

 species, with three distinct seasonal phases, and with a much-banded 

 caterpillar; the other into a yellow species, without distinct seasonal 

 phases, but very variable, and with a caterpillar in which are no traces 

 of sub-dorsal bands. 



And in Hagenii, we find an intermediate species of a ver}'' interesting 

 nature. The color is yellow, lighter than is usual in Philodice, but 

 varies in that respect, many being very green, and a large percentage, 

 especially of the females are not yellow, but of a peculiar shade, a 

 sort of buff-yellow, a shade not seen in Philodice. Considerably more 

 than half the females as reported by Mr. H. W. Nash, of Pueblo, Col., 

 who has paid great attention to this form, are of this butf yellow, and 

 the males frequently show more or less of it, and occasionally have a 

 flush of orange. The markings of Hagenii resemble those of Eury- 

 theme and Philodice, in the discal spots, the extra discal points on 

 both wings, the patch at outer angle, the shape of the black borders; 

 but there is a closer resemblance in the borders of many of the females 

 to Eurytheme than to Philodice, these being very wide, and on hind 

 wings nearly rea.-hing the cell, completely enclosing more or less defin- 

 ite yellow spots. Mr. Mead agreed with me twelve years ago, after 



*The eggs of all species of Colias far as known, are same shape, spindle-shaped, 

 ribbed vertically, and so alike that I doubt if any two species can be di'^iinguished by that 

 stage; the young larvfe and generally up to second moult, are almost or quite precisely 

 alike also; after that, if there are larval dififerences. they manifest themselves in variety of 

 bands or spots, the general shape and color remaining closely alike in all species to 

 maturity; and the chrysalids all have same form. This shows community of descent. 



