312 NORTH AMERICAN FAUNA. [No. 7. 



reaching an altitude of 1,310 meters (4,300 feet) on the southwesterly 

 slope exposures, but falling a little short of the extreme limit of the 

 scattered patches of Larrea in the same canon. 



Indian Spring Valley. — Common throughout the valley in Larrea. 



Oasis Valley. — Occurs sparsely in the lower part of the valley along 

 with Larrea, both species here finding their northern limit in this part 

 of Nevada. 



Grapevine Canon. — Franseria comes up in Grapevine Canon from 

 Death Valley and reaches up on the southern slope of Gold Mountain 

 as high as 1,610 meters (5,300 feet) in company with Larrea. (It was 

 not found in Sarcobatus Flat or in Meadow Creek Valley.) 



ARIZONA. 



Common with Larrea in the Valley of the Virgin near the mouth of 

 Beaverdam Creek, and ranging thence easterly up the west slope of 

 the Beaverdam Mountains to 1,160 meters (3,800 feet). 



UTAH. 



Santa Clara Valley. — Occurs sparingly in the lower part of the val- 

 ley, disappearing a little above 1,220 meters (4,000 feet). 



Franseria eriocentra. 



This species was first found at the mouth of Beaverdam Creek in 

 northwestern Arizona. On the opposite side of the mountains it is com- 

 mon in parts of the Santa Clara Valley in Utah. In Nevada it is abun- 

 dant in the higher parts of Pahranagat Valley, whence it ranges up 

 through a caiioniu the Hyko Mountains 5 it reaches the summit of the 

 pass over the Pahranagat Mountains (1,825 meters or 6,000 feet) from the 

 west (Tinrpahute) slope $ and occurs also at Hungry Hill Summit, 

 whence it extends southerly to about 1,675 meters (5,500 feet). 



Encelia frutescens. 



This species is common in places on the Mohave Desert, whence it 

 ranges up completely through the open cation leading from Mohave 

 to Tehachapi Valley (altitude of divide 1,100 meters or 3,600 feet), and 

 up the east slope of Walker Pass to 1,430 meters (4,700 feet). 



Artemisia tridentata. 



This species, the true aromatic sagebrush of the Great Basin, does 

 not grow anywhere in the deserts of the Lower Sonorau zone, but be- 

 gins with the Upper Sonoran and ranges thence northward over the 

 plains of the Transition zone, and on many mountain sides covers the 

 gravel slopes well up into the Boreal. Iu the southern part of the 

 Great Basin, therefore, it was found only on the mountains. Coming- 

 down from the plains of Oregon, Washington, and Idaho, it covers the 

 whole of the northern part of the State of Nevada, and California east 

 of the Sierra Nevada, and reaches southward uninterruptedly along 

 the bottom of Owens Valley nearly to Owens Lake, and still further 

 south along the Sierra, White, and Inyo mountains. On the treeless 



