ZOOLOGY. 129 



These "caches" are capriciously selected. At the cascades of the Columbia I was told by 

 a storekeeper that boots, empty kettles, &c., would be chosen, and that he had found in a boot 

 a pint of rice, together with other things which had been brought together, grain by grain, and 

 bit by bit, by these industrious animals. Like other rats, it is principally nocturnal in its 

 habits. 



Before the advent of the brown rat skunks were their principal enemies, who still, where 

 they exist, hunt them indefatigably, under and in the houses and outbuildings of the settlers . 

 I was told that the specimen I obtained, of which the measurements are given below, was not so 

 large as are sometimes seen. From the appearance of the teeth, &c., of my specimen, I judge 

 that it was a full-grown adult. 



Measurements of specimen 149, male, JciUed at Neiv Dungeness, W.T., Straits of Fuca, Jan., 21,1857. 



From nose to occiput 2.38 inches. 



From nose to base of tail 9.75 do. 



Tail vertebra 7.12 do. 



Tail to end of hairy tip 8.38 do. 



Height of ear posteriorly (from plane of occiput) 1.30 do. 



Hind foot, heel to end of longest claw 1.75 do. 



Pore foot, heel to end of longest claw 1.12 do. 



All the feet, belly, under surface of tail, and inside of legs tvhife. Top of head plumbeous, 

 brownish gray. Sides of back brownish gray; middle of back darker. Upper surface of tail 

 plumbeous. White hairs of the flanks plumbeous at their bases; those of the middle of the 

 breast white to their bases, but tinged with yellow on the surface, especially a spot about the 

 size of half a dollar around the umbilicus, which is quite of a soiled j'ellow appearance. The 

 settlers say this spot is persistent, being found on all specimens. — S. 



ARVICOLA TOWNSENDII, Bach man. 

 Oregon Ground Mouse ; Oregon Salt Meadow Mouse. 



[See Baird, Gen. Rep. p. 527.] 

 Townsend's meadow mouse, also called the salt-marsh rat, is found on the tide prairies and 

 salt meadows bordering Puget Sound. It is very common on the salt meadows along the Straits 

 of Fuca, where, at New Dungeness, I obtained a specimen. On the potatoe fields on the rich 

 "bottom lands" in the neighborhood of these marshes they are quite destructive to that vege- 

 table. The marshes are very much "cut up" by narrow little trails and paths which they 

 treivel upon. These are about 2 inches wide and well beaten, looking much like bufi'alo trails 

 in miniature. These mice are very numerous at Dungeness, so much so that Mr. Madison in- 

 forms me that he has killed several hundred in a day while ploughing. 



Measurements of specimen 150, obtained hy me at New Dungeness January 27, 1857; male. 



From nose to occiput, about 1-^0 inches. 



From nose to base of tail 5.87 do. 



From base of tail to end of vertebrae ■ 2- -5^ do. 



From base of tail to end of hairy tip 2.68 do. 



17 Q 



