GENUS CHIONOBAS 199 



hunter comes within ten yards of them. The female is rarely seen ; 

 she has a furtive, rapid flight when hunting for a place to lay her 

 eggs, and at other times remains hidden. 



The determination of this species is from the under side, the 

 striations being as depicted in the plate, somewhat intermediate 

 between the two preceding species. But the collector is never in 

 doubt, for Iduna's habitat is entirely different from that of 

 any other species, and no two species of these large Chionobas are 

 ever found in any one locality. 



288. Chionobas Ivallda. 



Plate XXVI ; Figures 288, a, b, c. 



Fig. 288, Male, Sierra Nevadas, 10,000 feet elevation, 

 1891 ; Author. 



a. Male, underside, Sierra Xevadas, 10.000 feet ele- 



vation, 1891 : Author. 



b. Female, Sierra Nevadas, 10,000 feet elevation, 



1891 : Author. 



c. Female, underside. Sierra Nevadas, 10,000 feet 



elevation, 1891 ; Author. 



Ivallda has much the same habits as Gigas, in that they live on 

 bare, rocky peaks, spending their whole time of the few days that 

 they have to live in flitting about to one rock after another, having 

 favorite alighting places on each rock. Such bare, wind-swept 

 piimacles seem to be inappropriate abiding places for such crea- 

 tures as butterflies, but they simply will not live in any other place. 

 These butterflies are very wary, too, and if you miss one it drops 

 over perpendicular precipices where only winged things and fly- 

 ing machines can go, and there they stay. Ivallda is another 

 species of "stranded butterflies." 



The eggs are laid singly on or among fine grasses ; the eggs 

 hatch in twelve days ; the larvae are nocturnal, feeding by night 

 and lying secreted by day. 



289. Chionobas Uhleri. 



Pl.\te XX\T : Figure 2S9, Female, Colorado ; from T. L. 

 Mead. 

 Uhleri is a Rocky Mountain species, and is noj; at present known 

 to fly on the mountains of the Coast. Yet it may be found on 

 mountains of moderate height, in any of the semi-desert localities 

 of the Great Basin or in Eastern Washington or Oregon. I mean 

 there is no apparent reason why it should not be so found. 



