468 PHYSICAL GEOGRAPHY. 



and 1844. The discovery of these, as detailed in his report, gives a 

 good idea of this portion of the country, and is as follows. It must be 

 premised that, in that report, what is now known as the Des Chutes 

 river, and which is one of the tributaries of the Columbia, is called 

 "Fall river" (Riviire aux Chutes); so, also, he spells Klamath lake 

 "Tlamatt." Speaking of the tributaries of the Columbia river, he says 

 (p. 200),— 



These streams are characterized by the narrow and chasm-like valleys in which they 

 run, generally sunk a thousand feet below the plain. At the verge of this plain they 

 frequently commence in vertical precipices of basaltic rock, and which leave only 

 casual places at which they can be entered by horses. The road across the country, 

 which would otherwise be very good, is rendered impracticable for wagons by these 

 streams. At such places the gun-carriage was unlimbered, and separately descended 

 by hand. Continuing a few miles up the left bank of the river, we encamped early in 

 an open bottom among the pines, a short distance below a lodge of Indians. Here, 

 along the river bluffs present, escarpments seven or eight hundred feet in height, con- 

 taining strata of a very fine porcelain clay, overlaid, at the height of about five hundred 

 feet, by a massive stratum of basalt one hundred feet in thickness, which again is suc- 

 ceeded above by other strata of volcanic rocks. The clay strata are variously colored, 

 some of them very nearly as white as chalk, and very fine grained. Specimens 

 brought from there have been subjected to microscopical examination by Prof. Bailey, 

 of West Point, and are considered by him to constitute one of the most remarkable 

 deposits of fluviatile infusoria on record. While they abound in genera and species 

 which are common in fresh water, but which rarely thrive where the water is brackish, 

 not one decidedly marine form is to be found among them ; and their fresh-water 

 origin is therefore beyond a doubt. It is equally certain that they lived and died in 

 the situation where they were found, as they could scarcely have been transported by 

 running waters without an admixture of muddy particles, from which, however, they 

 are remarkably free. Fossil infusoria of a fresh-water origin had been previously de- 

 tected by Mr. Bailey in specimens brought by Mr. James D. Dana from the tertiary 

 formation of Oregon. Most of the species in those specimens differed so much from 

 those now living and known, that he was led to infer that they might belong to extinct 

 species, and considered them also as affording proof of an alternation, in the forma- 

 tion from which they were obtained, of fresh- and salt-water deposits, which, common 

 enough in Eiu-ope, had not hitherto been noticed in the United States. Coming evi- 

 dently from a locality entirely different, our specimens show very few species in com- 

 mon with those brought by Mr. Dana, but bear a much closer resemblance to those 

 inhabiting the north-eastern states. It is possible that they are from a more recent 

 deposit; but the presence of a few remarkable forms, which are common to the two 

 locahties, renders it more probable that there is no great difference in their ages. 



