138 REPORT OF COMMISSIONER OF FISH AND FISHERIES. I 
rendering it unsightly. Specimens collecte d by Dr. Jordan the previous 
year had been examined by him, but observations were desired on 
fresh material and in relation to the life history of the species. 
The party reached the park about the middle of July, and, provided 
with a very complete outfit, began at once their axdinth Seaman which 
were continued until August 30. The ground gone over was prac- 
tically the same that had been traversed by Dr. Jordan in 1889, in- 
cluding the Gardiner, Madison, and Yellowstone river systems on the 
Atlantie slope of the continental divide, and that of the Snake River on 
the Pacific slope. Collections were made in 43 localities. The princi- 
pal fishless waters visited were Shoshone and Lewis lakes, the upper 
Gibbon and its tributaries, the Firehole and its branches, Goose Lake, 
Twin Lakes, Swan Lake, and Tower Creek. The effects of geyser and 
hot-spring overflow were studied especially on the Firehole and on Alum 
Oreek, and of the intervention of falls on the Gibbon River and some 
of its tributaries. The highest waters examined were Mary Lake, 
having an altitude of 8,200 feet, anda small lake, near Norris Pass, ab 
about the same level. Tined ps ing was carried on in Yellowstone Lake 
to a depth of 195 feet. The general collection of specimens obtained 1 is 
very large, and has been sent to the State Laboratory of Natural His- 
tory, at Champaign, Il, where it is being carefully studied under the 
direction of Prof. Forbes. It is considered to be sufficiently complete 
to explain the biological conditions existing in those lakes, ponds, riv- 
ers, and creeks which are devoid of fishes, in such as have only a single 
species of fish, and again in others supporting from 3 to 8 species each, 
Awaiting the preparation of Prof. Forbes’s report, we are able, in this 
connection, to present only a few of his preliminary conclusions, whieh 
are as ee B° 4 
The waters of the park, wherever they were examined, were found to 
provide a fair amount, and often an abundance, of animal life suitable 
as food for the ordinary carnivorous fishes, the fishless areas being no 
less well supplied in this respect than those already containing trout. 
These observations, therefore, support those of the ichthyologists, that 
the peculiar distribution of the fishes in this region can be explained 
alone from its topographical features, which have had no notice 
effect upon the distribution of invertebrates. Collections made both 
above and below the falls in certain rivers show that these obstructions 
to fish migrations have in no way interfered with the dissemination of 
the lower forms. The scarcity of fresh-water mussels and crayfishes 
is probably due to the chemical condition of the waters, especially in 
the absence of lime. The former were found only in Cation Cree 
where the living specimens were greatly eroded and the dead she 
rapidly decalcified. Crayfishes have also been recorded from only a 
single stream. No isopod crustaceans were discovered, and amphipods 
were very irregularly distributed, being very abuilanpe in some places 
and entirely wanting in others. rh phyllopod crustaceans were CO. 
