THE FISHES OF THE SACRAMENTO-SAN JOAQUIN BASIN, WITH A STUDY OF 
THEIR DISTRIBUTION AND VARIATION. 
By CLOUDSLEY RUTTER.@ 
The following report embodies the results of studies conducted incidentally to an 
investigation of the natural history of the young salmon. The primary object was to 
determine the distribution of the various species of fishes found in the Sacramento- 
San Joaquin basin, but the identification of the species necessitated a study of their 
variations, which has proved of equal interest. The determinations are based on 
large collections made in 1898 and 1899 by the author with Mr. Fred M. Chamber- 
lain, of the Bureau of Fisheries, Mr. N. B. Scofield, ichthyologist of the California 
Fish Commission, and Mr. W. S. Atkinson, a student at Stanford University, as 
associates. 
The report includes notes on the geography of the basin, with a synopsis of the 
streams in which collections were made; a review of the various papers in which other 
collections from this region have been recorded; a key to the species known to inhabit 
the basin; detailed discussion of the variations and the local distribution of the native 
species; a list of the anadromous species; and a list of the species that have been 
introduced. 
GEOGRAPHY OF THE BASIN. 
The great central basin of California, drained by the Sacramento and San Joaquin 
rivers, has for its eastern rim the Sierra Nevada and for its western the coast ranges. 
Spurs from these two ranges form the southern boundary of the basin, and the ranges 
themselves meet at the north, culminating in Mount Shasta, and form the northern 
boundary. The outlet of the basin is through a notch in the middle of the western 
rim, occupied by San Pablo and San Francisco bays. The shape of the basin is that 
of a long ellipse, with its major axis curved concentric with the coast line. Its length 
is about 450 miles and its width about 125 miles. Altogether the Sacramento-San 
Joaquin basin, including Pitt River drainage but excluding Goose Lake and San Pablo 
and San Francisco bays and their immediate drainage, has an area of 58,250 square 
miles, which is greater by 1,600 square miles than the state of Illinois. Its northern 
aThe manuscript for this report, submitted by Mr. Rutter at the completion of the studies upon which it is based, 
had not, at the time of his death, in 1903, been arranged in final form for printing. The information it contains, how- 
ever, is considered of interest and value, and the puper is accordingly presented with such revision as is possible under 
the circumstances, the modifications that have been made relating chiefly to the form and order in which the material is 
presented. 
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