EXPLOKATIONS IN YELLOWSTONE NATIONAL PAEK. 
53 
It is said the bears are often seen goiug about the shores of the lake picking up the 
dead fish. 
10. Cottu.s bairdi Girard. (Yar. punctdilatus.) (Plate X, Fig. 12.) 
The “Miller’s thumb” or “blob” is found in great abundance in the grassy bottoms 
of Madison River, Gibbon River, and Canon Creek. In Gibbon River it is fouud 
above the falls as well as below it, an anomaly of distribution as yet uuexitlained, 
uuless we call in the aid of the Osi)rey or some similar agency. It is said tliat the 
species is found also in the Yellowstone below the Park. 
The specimens taken by us in the Gibbon and Canon Creeks, as well as those procured 
by Mr. Lucas in Horsethief Spring are identical with specimens taken by ns from Eagle 
River, Colorado, and iu other tributaries of the Colorado. All of them belong to tlie 
variety or species named Potamocottus punctulatus Gill, although the dark spots are 
generally coarser and more diffuse than is shown iu Professor Gill’s figure.* 
In the specimens from the Park tlie band of palatine teeth is broad ; there are no 
prickles on the skin. The head is 3^ iu length and the rays are D. VII-17 ; A. 13; 
y. I, 4. . 
Comparing these with specimens {Cottus bairdi caroUnce), from Mammoth Spring, 
Missouri, the differences seem well marked. Var. jxtactM/ntw.v has the head blunter, 
lower and more rounded, the cheeks moi'e tumid and the top of the head without 
median longitudinal depression. Var. carolinw has the axil prickly, the outline of the 
head angular, the top of head with a median longitudinal depression from snout to 
nape, and the body has broad distinct black cross-bars. 
These two forms seem like distinct species, but other specimens are intermediate; 
specimens from Torch Lake, Michigan, agree with ininctulatus iu color, and are inter- 
mediate in form; specimens from White River, Indiana, are colored like var. euro linre, 
but are iuterinediate in form. Apparently punctulatm should be recognized as a sub- 
species but its range and distinctive characters are yet to be made out in detail. 
THE STREAMS AND LAKES OP THE PARK. 
The following is the substance of our field-notes on the physical characteristics 
of the streams and lakes of the Park: 
YELLOWSTONE BASIN. 
The Yellowstone River. — The Yellowstone River drains an area of 1,900 
square miles, or about half the surface of the Park. It has its rise in the Continental 
Divide, to the southeastern limit of the Park. One of its tributaries, Atlantic Creek, 
Hows to the eastward by the side of a low part of the Divide, known as Two-Ocean 
Pass. On the opposite side of this pass, at a distance of about one-eighth mile, flows 
Pacific Creek, iu the opposite direction, though parallel with Atlantic Creek. Pacific 
Creek is a tributary of Snake river. The Divide between the Yellowstone and Snake 
River is a marshy meadow, more or less overflowed in spring, its whole width scarcely 
more than an eighth of a mile. It is supposed that the stock of trout iu the Yellow-^ 
stone, above the falls, must have originally come from Pacific Creek. Whether the 
lower Yellowstone and the upper waters of the tributaries of the Missouri were stocked 
in this way is less certain. If the trout of the Missoui’i came across Two-Ocean Pass 
Ichthyology Captain Siinpsoii’a Kept. Expl. Basin of Utah. 
