ZOOLOGY—MAMMALS. 
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very short. Middle claw 5§ lines above; below, occupying nearly two fifths of the hand ; its toe about two-eighths. First 
finger or thumb very short, barely reaching over two-sixths the hand. 
Color. —Above, dusky chestnut brown, but slightly mottled on sides and beneath with an ashy brown tinge. Cheek pouches 
whitish at the bottom, the line of demarcation indistinct, and the brownish color of the marginal region running down into 
the pouch. Tail grayish ; dusky above. 
Many specimens were collected at Fort Steilacoom, (8, 840;) also several at Fort Dalles, (59.) 
No. 59, Female.—Dalles, April 25. 
Inches. Lines. 
Nose to insertion of tail. 5 4 
Tail. 1 10 
Nose to ear. 1 4 
Central claw of fore foot about... 4 
Extreme stretch. 7 7 
PEROGNATHUS FASCIATUS, P r. Max. 
Perognathus fasciatus, Pr. Max. Nova Acta C. L. C. Acad. XIX, i, 1839, 369 ; tab. xxxiv.— Ib. Reise innere Nord- 
Amerika, I, 1839, 449. 
Aun. & Bach. N. Am. Quad. Ill, 1854, 341. 
Baird, Gen. Rep. Mammals, 1857, 420/ 
Sp. Ch. —Considerably larger than the house mouse. Tail as long as the body without the head. Antitragus conspicuously 
lobed. Soles naked. Above reddish yellow, closely lined with black ; fore legs all round, feet and under parts white ; a pale 
reddish yellow immaculate band on each side. 
This animal was found in the vicinity of Fort Union, Nebraska. 
PEROGNATHUS MONTICOLA, Baird. 
Baird, Gen. Rep. Mammals, 1857, 422. 
Sp. Ch. —Antitragus lobed ; soles naked. About as large as the domestic mouse. Tail rather shorter than the head and body, 
fully coated with hair. Hind feet rather short. Color above mixed cinnamon and dusky ; flanks scarcely clearer, beneath 
white ; tail colored to correspond with these regions. Hairs below, as well as above, plumbeous at base, those above exhibiting 
this color for nearly two-thirds their length. Outside of fore leg dusky to the wrist. 
St. Mary’s Mission, Rocky Mountains. 
PEROGNATHUS FLAYUS, Baird. 
PerognathusJlavus, Baird, Pr. A. N. Sc. Phils. VII, April, 1855, 332. 
Gen. Rep. Mammals, 1857, 423. 
Sp. Ch. —Considerably less than the common mouse. Tail equal to or less than the head and body, scarcely different in 
color above and below. Hind feet short. Abovb, yellowish buff, with dusky tips to some of the hairs ; clearer on the sides. 
Beneath, snowy white to the roots of the hair. Fore leg white to the shoulders. Hairs on the back plumbeous only on their 
basal half. 
Found between Milk and Maria rivers, Nebraska. 
JACULUS HUDSONIUS. 
Jumping Mouse. 
Dipus hudsonius, Zimmermann, Geog. Geschichte, II, 1780, 358. 
Meriones hudsonius, Aud. & Bach., N. Am. Quad. II, 1851, 251 ; pi. lxxxv. 
Jaculus Hudsonius, Baird, Gen. Rep. Mammals, 1857, 430. 
Sp. Ch. —Above, light yellowish brown, lined finely with black ; entire sides yellowish rusty, sharply defined against the 
colors of the back and belly. Beneath, pure white ; feet and under surface of tail whitish. Body, 2.75 to 3.50 inches ; tail, 
4.50 to 6.00 ; hind feet, 1.10 to 1.30. 
Specimens collected at Steilacoom. 
MUS DECUMANUS, Pallas. 
Brown Rat; Norway Rat. 
Baird, Gen. Rep. Mammals, 1857, 438. 
This species was unknown at Steilacoom until about five years ago, when it was introduced 
