
342 B. N, A. BOUNDARY COMMISSION. 
tainly occurs in the Assineboine region, Argynnis Edwardsii of the Yellowstone is 
replaced by A. Bremnerii in the Assineboine, and probably also by A. Aphrodite, 
although this was taken at Woody Mountain. The two species of Eurymus, however, 
were taken in both regions, and a species of Argynnis (A. Nevadensis) was also found 
common to both. 
The watershed between the Assineboine and Saskatchewan basins on the one 
side, and the basin of the Missouri, of which the Yellowstone is a tributary, on the 
other—a watershed which follows a course nearly coinciding with the annual 
isotherm of 45° Fahr. (corrected for altitude)—would seem, therefore, to be, in all pro- 
ability, the dividing line between a more northern and a more southern fauna; or 
perhaps, more correctly speaking, between a north-eastern and a south-western fauna. 
The northern branch of the Missouri, to be sure, intervenes between the regions tra- 
versed by Messrs. Dawson and Allen, but its fauna must unquestionably have a facies 
essentially similar to that of the Yellowstone. We shall, however, look with interest 
for Mr. Edwards’ forthcoming report upon the butterflies collected by Dr. Coues 
through this region, to see whether the facts will add to, or detract from, the weight 
of the considerations we have presented, from the scanty material at our disposal _ 
CamsripGEe, U.S., March, 1875. 
BUTTERFLIES. 
1. @neis Uhleri—A single male, remarkably small, measuring but 45-5 mm. 
in expanse, was taken in the vicinity of Woody Mountain, between the middle of 
June and July 7. 
2. Enodia Portlandia—Two males were taken in the neighbourhood of the Lake 
of the Woods between the middle of July and the middle of August. 
3. Canonympha Ampelos—A badly broken specimen, probably referable to this 
species, was taken at Dufferin. 
4. Danaida Plexippus.——A male was taken in the Red River valley, June 20. 
5. Basilarchia Arthemis—A female was taken at Dufferin between June 21 and 
26, and another near the Lake of the Woods between the middle of July and the 
middle of August. The latter specimen is interesting from its large size, (expanding 
84mm.) and in the extent and dullness of the red spots of the under surface, in 
which it begins to show no inconsiderable resemblance to B. Weidemeyeri. 
6. Polygonia Progne—A male was taken in the vicinity of the Lake of the 
Woods between the middle of July and the middle of August; a female was taken at 
Dufferin. 
7. Papilio Antiopa—One specimen was taken at Dufferin between June 21 and 
26; another at the Lake of the Woods between the middle of July and the middle of 
August. 
8. Aglais Milberti—A single male was taken near the Lake of the Woods between 
the middle of July and the middle of August. 
9. Vanessa cardui—Common at Dufferin, June 14. 
10. Argynnis Aphrodite—One male was taken in the vicinity of Woody Mountain 
between June 15 and July 7, and another near the Lake of the Woods between July 
15 and August 15. 
_ ll. Argynnis Nevadensis—A single fresh male was taken at the close of June at 
Wood End; fresh specimens of both sexes between Woody Mountain and the base of 
the Rocky Mountains, from July 15 to August 7. 
12. Argynnis Bremnerii—A male was taken at Dufferin. 
13. Brenthis Bellona —A male was taken at Dufferin in June, 
