ZOOLOGY. 59 



through mountain meadows green as emerald, and daisy-decked, in a region never before pro- 

 faned by the foot of a white man, and unoccupied by savages, that we found the beaver in num- 

 bers, of which, when applied to beavers, I had no conception. The sides of these streams were 

 literally lined with their habitations, though we never saw their houses, and seldom a dam 

 made by them, but usually their burrows pierced the sides of the stream, a sufficiently large 

 and long excavation being made to form warm, roomy, and comfortable quarters. From the 

 point where these burrows terminate in the water, trails lead off to thickets of willow or pine, 

 where the beavers find their food. These thickets exhibit the most surprising proofs of the 

 power and industry of these animals : whole groves of young pine trees cut down within a few 

 inches of the ground, and carried off bodily. So well was the work done that one could hardly 

 resist the conviction that the woodman's axe had not there been plied vigorously and well. 

 These trees, when felled, are cut into convenient lengths and carried to the burrows, there to 

 be stripped of their hark, and then thrown into the stream. We often saw trees of considera- 

 ble size cut down by the beavers ; the largest which I noticed was a spruce pine twelve inches 

 in diameter. 



In California the beaver is also quite common, though less so than in Oregon. It is found in 

 the streams flowing into the Sacramento, both from the coast range and from the Sierra Nevada. 

 On Cottonwood creek, which comes down from the coast range, near Fort Reading, they abound, 

 and have cut the cottonwood trees, which line the banks of the stream, of a diameter of from 

 fifteen to eighteen inches. 



To any one who has never seen the beaver in his native haunts the accounts of his mechan- 

 ical skill and general intelligence, as exhibited in his dams and "clearings," must seem almost 

 fabulous ; and when he has seen these with his own eyes he cannot fail to feel that the pro- 

 found respect entertained by the Indians and trappers for this sagacious animal is in a great 

 degree deserved. 



The value of beaver skins has so much depreciated that they were offered to some of our 

 party, by the bale, at twenty-five cents each. 



THOMOMYS BOEEALIS. 



Geomys borealis, Rich., Report British Asso. for 1836, V. 1837, 156. — (Said here to come from Saskatchewan.) 

 Pseudostoma borealis, Acd. & Bach., N. Am. Quad. Ill, 1853, 198 ; pi. cxlii. 

 Geomys toumsendii, (Rich. RIss.) Bach., J. A. K. Sc. Phila. VIII, i, 1839, 105. 

 Thomomys borealis, Baird, Gen. Rep. Mammals, 1857, 396. 



A single specimen of this very doubtful species was collected at Canoe creek, California. It 

 will, in all probability, prove to be only a variety of T. douglasii. 



JACULUS HUDSONIUS. 



Jumping Mouse. 

 Dipus hudsoniw, Zimmermann, Geographische Geschichte, II, 1780, 358, (based ou Pennant's long-legged mouse 



of Hudson's Bay.) 

 Meriones hudsonius, Aim. & Bach., N. Am. Quad. II, 1851, 251 ; pi. Ixxxv. 

 Jaculus hudsonius, Baird, Gen. Rep. Mammals, 1857, 430. 



Sp. Ch. — Above, light yellowish brown j lined finely with black ; entire sides yellowish rusty, sharply defined agains* 

 the colors of the back and belly. Beneath, pure white ; feet and under surface of tail whitish. Body measuring 2.75 to 

 3.50 inches ; tail, 4.50 to 6.00 inches; hind feet, 1.10 to 1.30 inches. 



A specimen of this species, collected at Canoe creek, California, agrees with all other western 

 ones in a decided superiority in size to eastern ones. 



