48 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
A small specimen (3 inclies long) from Beaverhead Biver has the depth and head 
about equal, each 4 in length of body. Upper half of its body covered with fine dark 
specks, most numerous on edges of scales where they form a dark border; alqng the 
region of the lateral line is a series of about fifteen steel-blue blotches, the vertical 
diameter greatest, much resembling the parr markings of young front and whitefish. 
Above these are many smaller spots or blotches of same color. (See PI. xxii.) 
Two specimens, 3-J and 3J inches long respectively, from Bed Bock Biver, have the 
steel-blue blotches very distinct, while the dark borders or lines between the rows of 
scales on the upper half of body have begun to break up into short, inky, zigzag 
lines each with one to eight or more angles. 
13. Salmo mykiss Walbaum. (PL xxiv.) 
The black-spotted or mountain trout is represented in the collection by specimens 
from the following localities: 
a. Swan River below Swan Lake, Montana. 8 
b. Flathead Lake 2 
c. Mission Creek near Ravalli, Montana.. . 1 
d. Jocko River, Ravalli, Montana 20 
e. Rattlesnake Creek, Missoula, Montana.. 7 
/. Lolo Creek, Missoula, Montana 9 
g. Big Blackfoot River, Bonner, Montana.. 1 
h. Little Blackfoot River, Elliston, Montana 12 
i. Cottonwood Creek, Deer Lodge, Montana 19 
j. Dempsey Lakes, Deer Lodge, Montana. . 12 
k. Browns Gulch Creek, Silver Bow, Mon- 
tana 3 
l. Lewis River just below Lower Falls 2 
m. Crawfish Creek just below Moose Falls. 2 
n. Snake River, President Camp, Wyoming. 9 
o. Pacific Creek 25 miles below Two-Ocean 
Pass 6 
p. Pacific Creek about 8 miles below Two- 
Ocean Pass 3 
q. Pacific Creek at Two-Ocean Pass 16 
r. Atlantic Creek at Two-Ocean Pass 20 
s. Atlantic Creek 1 mile above its mouth. . 1 
f. Mouth of UpperYellowstone River 2 
u. Meadow Creek near its mouth 6 
v. East Fork Gardiner River above falls. . 1 
w. McClellan Creek near Helena, Montana . 2 
This species is found abundantly in all suitable streams and lakes explored by us. 
Besides the 135 specimens from the Columbia basin and the 32 from the Missouri 
side, a great many individuals were examined in the field which were not preserved. 
In addition to the above, numerous specimens in the collections in the U. S. National 
Museum were compared with those of my own collection. The whole amount of mate- 
rial examined goes to show the correctness of the conclusion reached by Dr. Jordan,* 
that all the native trout of the Park belong to a single species, and that Salmo clarkei , 
Salmo lewisi , etc., can not be recognized even as varieties. 
The fact that there is a free waterway over Two-Ocean Pass, by fneans of which 
trout can pass readily from either side of the u Divide ” to the other, as explained else- 
where in this report, is of great importance in showing that the trout of the two sides 
can not be regarded even as geographical forms. The differences that are observable 
among different specimens do not exist as differences between Missouri and Columbia 
drainage specimens, but rather as slight peculiarities due to the nature of each partic- 
ular stream. This will appear evident from a comparison of the following color notes, 
based upon specimens of different sizes and from different places : 
A specimen 4f inches long, from McClellan Creek, Helena, Montana: Side with 
about ten dark blotches lying on the lateral line, the vertical diameter being the greater; 
a series of about a dozen larger, rounder ones along middle of space between lateral 
line and middle line of back; among and about these are numerous small spots; spots 
Bull. U. S. Fish Commission, vol. ix, 50, 1891. 
