Butterflies of the Mountain Summits. 



93 



Although there are, as I have just said, but few distinct 

 species— indeed, authorities recognize but two in California- 

 yet each of these species is composed of a number of fairly 

 recognizable varieties or sub-species, so that the careful collec- 

 tor can certainly find at least half a dozen recognizably diifer- 

 ent forms of California Parnassians. The two admitted 

 species in our fauna are Parnassius clodius, whose varieties 

 are found only in the mountains of the Pacific Coast, and Par- 

 nassius smintheus, whose varieties occur both in the Rocky 

 Mountains and the Sierra Nevada. 



All the Parnassians are rather large butterflies, expanding 

 from two and a half to three and a half inches, but showing 

 much variation in size, specimens from the higher altitudes 

 being often much smaller. The wings have a curious, almost 

 translucent, solid white ground color — in one Alaskan species 

 the color is pale lemon-yellow — and the heavy body is clothed 

 with gray and dark hairs. The hind wings bear on both upper 

 and lower sides a few irregularly circular reddish spots, some- 

 times with a whitish center. One or two of these spots occur 

 also on the fore wings of certain varieties. There are also, 

 especially on the fore wings, a few blackish spots or small 

 blotches, and the inner margin of the hind wings is broadly 

 bordered with blackish. There is usually a faint dark band 

 across the fore wings near the outer margin. 



The flight is irregular and jerky, usually rather slow and 

 near the ground. They are easily seen because of their large 

 size and whitish color, and are not difficult to catch. They 

 occur in the Rocky Mountains in considerable numbers at 

 about 8,000 feet altitude, in the characteristic glacial parks of 

 the Front Range. In California they range from much lower 

 altitudes to much higher ones, records of captures at nearly 

 sea-level and at 12,000 feet having been made. 



The peculiar faintly smoky translucent appearance of the 

 wings of the Parnassians is due to the fact that the "butterfly 

 dust" or scales which cover the wings and on which all color 

 and pattern of butterflies depends, are not, as in other butter- 

 flies, short, flat and broad, and closely and regularly arranged 

 in a complete shingling covering over the wing surfaces, but 

 are narrow, rather sparse, and irregularly arranged, and thus 



