The Moths and Butterflies 457 



yellow spots on the fore wings and two on the hind wings; besides there 

 are some scattered red spots and some other yellow ones. The caterpillar 

 is black, spiny, and banded with orange-red; it feeds chiefly on Chelone 

 glabera, a kind of snakehead. On the Pacific coast the chalcedon, 

 Melitaea chalcedon, is the most abundant checker-spot, although several 

 other species are common. It has black wings spotted with red and 

 ocher-yellow ; the spiny black caterpillar feeds chiefly on Mimulus and 

 Castilleja. 



The satyrs or meadow-browns are a group of fifty or more beautiful velvet- 

 brown butterflies whose markings consist chiefly of eye-spots, large and small, 

 on both upper and under wing surfaces. A number of species are abundant 

 and familiar, but a majority live exclusively in mountain states, and especially 

 in the west. The common wood-nymph, or eyed grayling, Cercyonis alope, 

 (PL X, Fig. i), is the most familiar eastern and middle state species. 

 A larger similarly patterned form, C. pegala, is common in the south. The 

 larvae of the meadow -browns feed on grasses, are pale green or light brown, 

 and have the last abdominal segment forked. On the Pacific coast one 

 of the most abundant autumn butterflies is the California ringlet, Cceno- 

 nympha calijornica, a small buffy-white member of this group with small 

 eye-spots only on the under side of the wings. A number of interesting 

 butterflies related to the meadow-browns are found only on mountain-tops 

 or in high latitudes (arctic region) the equivalent in life conditions of high 

 altitudes. In the Rocky Mountains on the peaks of the Front Range (13,000 

 feet altitude) I have struggled, gasping in the thin air, after beautiful frail 

 little brown and grayish butterflies, (Eneis and Erebia. Far above timber- 

 line on bleak mountain-tops, masses of broken granite overspread for great 

 spaces with lasting snow, these hardy little flutterers live successfully. At 

 the edges of the great snow-fields are patches of alpine flowers, fragrant 

 dwarf forget-me-nots and buttercups, which furnish food and interest for 

 them in the solitude of the high peaks. 



The mountain-top butterflies of the White Mountains, of the Rocky 

 Mountains, and of the Sierra Nevada are closely allied; indeed individuals 

 of the same species are found on the summit of Mt. Washington and on 

 the crest of the Rockies, and nowhere between these two widely separated 

 localities. The question as to how this interesting condition of things came 

 about would be answered (by the student of distribution) as follows: In 

 glacial times the species probably ranged clear across the continent. With 

 the retreat of the great continental ice-sheet, while most of the butterflies 

 followed it closely north, or became in successive generations slowly adapted 

 to the temperate life conditions, some few probably followed up the slowly 

 retreating local mountain glaciers. In time, therefore, the descendants 

 of these arctic-loving species found themselves still under truly arctic con- 



