104 BULLETIN UNIVERSITY OF MONTANA 



the lakes and rivers, and being able to live on the mountain sides during 

 the damp spring months, in summer disappearing from sight until the fol- 

 lowing spring. As the ascent was made and the struggle became fiercer 

 the size of the shells became reduced, this form being much smaller than 

 the variety cooperi. But still others ascended to higher realms and are 

 mow found on the highest and bleakest of rocky slopes. This P. strigosa 

 ■var. alpina is no doubt the result of this gradual ascent. In size it is 

 small, being really diminutive. The struggle is great. Food is scarce. 

 To support so large a body as the small form lower down, or the ordinary 

 specimen at the lake or creek, is impossible. Consequently, there has 

 ■been a change in structure to accommodate the changed conditions, and 

 the shell is much reduced in size. The form, cooperi, has not been found 

 by the writer above 4,000 feet. The small variety is found from 5,000 feet 

 to 7,000 feet in the west, and higher in the east. The diminutive variety 

 lias been taken on this occasion at an altitude of 8,500 feet and from that 

 nearly to the top. The same diminutive shell was later taken on Mc- 

 Donald peak at an altitude of 8,000 feet to 9,000 feet. 



Plate XXVII will give the reader a better idea of the size and rela^ 

 tionships of the shells before mentioned than can be obtained from a de^ 

 scription. 



The summit was reached at 4:15 in the afternoon. It was completely 

 t)are of vegetation save for one little straggling specimen on the west- 

 ■ern edge, catching the rays of the sun, and not sufficiently far along in 

 growth to make a determination. The aneroid registered 9,150 feet. Al- 

 though the sky was cloudless a few pellets of snow came from some place 

 and struck us in the face. At our feet was an immense snow drift on 

 which the camera was planted and which was covered with goat 

 tracks. 



The sight was fine. No one can tell the glories, beauties, or de- 

 pict the awfulness of the view from one of the heights of the Mission 

 range. To the west is the twin peak of the one we have ascended, show- 

 ing beautifully the stratification, and the formation of the mountain. Be-- 

 yond this peak the mountain drops almost abruptly to the plain. To the 

 north the range appears as one vast jumble of peaks and ridges, though 

 ■of course there is order in it all. Reference is made to the impression. 

 To the east the Jocko peaks rise abruptly from the snow fields, old snags 

 that appear incapable of being ascended. A view of these is given in 

 Plate XXI. Between Sinyaleamin and the Jocko peaks is a large gla- 

 •ciated region, no doubt the former ice region supplying the material for 

 the moraine at Sinyaleamin lake, or the lakes toward the east. At the 

 foot of the old Jocko crag is a small lake, filled with slush snow and ice, 

 as viewed from our distance, and which has been christened Snow lake in 

 •consequence. This Snow lake is in the drainage of Sinyaleamin lake, 

 the waters entering Snow lake, overflowing, passing down over the rapids 

 into Sinyaleamin lake, and on to Mission creek. To the south Mount 

 Ix) Lo, in the Bitter Root range, may be seen 75 miles away. The Bitter 

 Root range. Cabinet and Swan ranges, the Mission range in the fore- 

 ground, the Kootenais and the Rockies, make a grand and beautiful pan- 

 orama. Thirty miles to the north may be seen Flathead lake, blue as the 



