BUTTERFLIES OF MONTANA. 93 



Eugonia J-Album in Western Montana. 



"This insect is generally rare," writes Holland in his Butterfly Book. 

 In several places in the western part of the state it may be taken in large 

 numbers. At the upper end of Echo Lake, next to the Swan range, we 

 have never failed to take it during our annual pilgramages to the summit 

 of the range, MacDougal mountain. The old submerged cabin in the 

 lake is a safe refuge. The cabin on the bank, now deserted, offers a 

 safe retreat from enemies save the human entomologist, who finds here 

 a great opportunity for capturing a rare specimen. 



But it is at Swan Lake that Eugonia J. album flourishes in its splen- 

 dor, magnificence and abundance. This beautiful little sheet of water 

 lies cradled between the Swan and Mission ranges. At its upper end, 

 on the eastern shore, are three cabins. The cabins are along the trail 

 which leads up the lake, through the Swan river forest above the lake 

 to the wagon road leading to Ovando, Missoula, and other places. A 

 clearing of a few acres is around the cabins. Dense woods come to 

 the clearings on all sides. In August the sun is intensely hot in the 

 small open patches about the cabins. About these small log huts, seek- 

 ing the shade of the rude porch or the interior of the stable, Eugonia J. 

 album was to be had by the dozens. They would alight on the logs of 

 the buidings, the stumps in the clearing, the fence rails, and the bark of 

 the living trees. After alighting they remained perfectly quiet, so that 

 one could carefully adjust the net over them, and with a quick jerk scoop 

 them into the net. In this way a half dozen were often fluttering in the 

 net at once. It was practically impossible to capture them on the wing, 

 so quickly can they dodge and so swiftly do they fly. 



When the butterflies alighted on the bark of the fir, cottonwood or 

 birch, upon which they were generally taken, they were almost invisible. 

 It was interesting to see them remain in the same quiet attitude on the 

 top rail of a fence or the skinned log in the cabin, where they were very 

 conspicuous, as on the trunk of a tree where they were invisible. Pro- 

 tective resemblance was in this species beautifully illustrated, and those 

 who made the trip to Swan Lake in August, 1903, will not soon forget 

 how the insects were controlled by instinct. 



Other insects were out, and were captured. Eugonia californica was 

 much less common than E. J. album, while an occasional Polygonia 

 faunus was picked up. The western admiral was rare. Robberflies were 

 out in abundance, as were also bees. Two species of flies were captured 

 which mimic bees, and a dozen species of butterflies were found in 

 greater or less abundance. Nowhere in Montana have we seen more 

 butterflies at one place or captured more in one day than at Groom's 

 cabin at the upper end of Swan Lake, when the species under discussion 

 was taken in such abundance. 



In early August, 1904, another visit was made to the cabins at Swan 

 Lake. J. Album was in much less abundance, and difficult to take be- 



