518 University of Califorma Publications in Zoology | Vou. 17 
Shelton, of the University of Oregon, furnished information which 
has been made the basis of some of the statements herein contained. 
The writer wishes to thank Drs. Joseph Grinnell and Walter P. 
Taylor for bringing this paper into final form for publication. 
Historica 
Present knowledge of the mountain beaver began with the arrival 
upon the coast of Oregon of the expedition under Lewis and Clark. 
This expedition went into winter quarters at Fort Clatsop, near the 
present site of Astoria, on December 8, 1805, In Clark’s notes (in 
Lewis and Clark, 1904, 3, p. 279) of Friday, December 13, 1805, 
appears the following entry: 
‘*The Clatsops leave us to day after a brackfast on Elk which they 
appeared to be very fond of before they left us they Sold me two robes 
of the skins of a Small animal about the size of a cat, and to Captain 
Lewis 2 Cat or Loucirva Skins for the purpose of makeing a Coat.’’ 
The ‘‘small animal’’ mentioned was what the explorers thought the 
Indians ealled ‘‘Sewelel,’’ if we are to judge by the notes of Lewis 
for February 15, 1806 (loc. cit., 4, p. 73), and February 26, 1806 
(loc. cit., pp. 109-110). 
The first published account of the mountain beaver was a modifica- 
tion of the above notes in the Biddle-Allen edition (1814) of the Lewis 
and Clark Expedition (see Coues, 1877, p. 591). And the first nat- 
uralist to study a skin of the animal was Richardson (1829, pp. 
211-213). 
The Wilkes Exploring Expedition collected two specimens of 
aplodontia, probably in the neighborhood of Puget Sound. T. R. 
Peale (see Coues, loc. cit.), who collected these specimens and later 
(1848) described them, remarks on the abundance of the species at 
““Puget’s Sound.”’ 
The next notice of the genus was by Audubon and Bachman 
(1854, 3, pp. 99-102), who quote Richardson and Lewis and Clark as 
first published, and add inferences drawn from the anatomy as to the 
habits, and some further statements concerning distribution. 
The naturalists of the Pacifie Railroad Survey, under the super- 
vision of 8S. F. Baird, were able to make valuable observations on the 
habits of aplodontia. Their findings together with those of other 
observers since then and up to the year 1916, are incorporated into 
the sueceeding parts of the present paper. 
