776 ZOOLOGY INSECTS. 



ignatiou as a variety, especially as those from Colorado are remarkably 

 constant to their type ; the seventy specimens taken showing scarcely a 

 trace of variation among themselves. In comparing the two forms, the first 

 noticeable point is the slender and delicate appearance of Callias ; in speci- 

 mens of each having the same breadth of wing the expanse of Callias is 

 one-fifth greater than that of Tyndarus. 



Among the minor points of difference may be enumerated the follow- 

 ing : In Tyndarus, on the under side of the primaries, the fulvous mark is 

 bordered by a brown band parallel to the margin ; while in Callias it shades 

 off insensibly, extending much nearer the edge at the center of the outer 

 margin than at the apex or external angle. The wavy bands and marblino- 

 are very indistinct in Callias, much more so than in any specimens of Tyn- 

 darus I have seen ; and in the males it has almost exactly the appearance of 

 moldiness. On the upper surface, the fulvous, which in Tyndarus forms 

 five or six well defined spots, in Callias is represented by a patch, covering 

 a considerable portion of the wing, and scarcely showing the nervures. 



CHIONOBAS, Boisd. 

 CHIONOBAS SBMIDEA, Say. 

 Hipparchia fiemidea, HARRIS, Insects Injurious to Vegetation. 



C. Semidea is exceedingly rare in Colorado, and is only found on the 

 extreme summits of the mountains. Near Twin Lakes, two specimens were 

 taken, and others seen at an elevation of 13,000 feet, on a very steep 

 mountain. The mountain side rose so precipitously that bowlders loosened 

 near the top might sometimes be watched in their descent till lost to view 

 tliree-quarters of a mile below ; and just at the summit where these butter- 

 flies were found the ascent was even more difficult than lower down. The 

 butterflies were very shy and wary ; when alarmed, they usually flew, not 

 along the side of the mountain, but either up or down, rendering pursuit 



almost impossible. 



UHIONOBAS UHLERII, Beakirt. 



Chionobas Uhlerii, REAKIRT, Proc. Ent. Soc. Phihi., 18(56. 



C. Uhlerii was abundant in the lower mountain regions of Colorado, 

 inhabiting grassy spots, and making only short flights when disturbed or 

 otherwise, soon alighting and being lost to view in the short dry grass. It 



