MAMMALS OP THE MEXICAN BOUNDAEY. 51 



6,150 feet (near Gallina Springs, San Jose Mountains). Its longi- 

 tudinal range, on the Mexican Line, is from the Dog Mountains to the 

 Pajaritos Mountains (Monuments Nos. 54 to about 138) . The largest 

 tree seen measur.ed 2.63 meters in circumference and 20 meters in 

 height (Clover dale, Grant County, New Mexico). 



QUERCUS ARIZONICA Sargent. 

 ARIZONA WHITE OAK. 



This oak, which in Arizona is commonly known as the white live 

 oak, to distinguish it from Quercus emoryi, which is called the 

 black live oak, is the commonest of the, genus along the Mexican 

 Border, perhaps excepting the Emorj' oak. It is a rather low, widely 

 spreading tree, with the short trunk from 1 to 4 feet in diameter and 

 20 to 60 feet in height. As a rule this species begins just above the 

 lower edge of timber, commencing a little higher than Quercus 

 ohlongifolia, with which it is associated in the lowest part of its 

 range. Its extreme vertical range is from 1,267 meters, or 4,157 

 feet (Guadalupe Canyon), to 2,500 meters, or .8,200 feet (San Jose 

 Mountain). Longitudinally its range coincides with that portion of 

 the Mexican Boundary Line which is formed by the parallel of 31° 20' 

 (Monuments Nos. 53 to 127). We found it in the Dog, San Luis, 

 Animas, Guadalupe, Cero Gallardo, Mule, San Jose, Huachuca, Santa 

 Cruz, Patagonia, and Pajaritos mountains. It belongs to the Transi- 

 tion Zone. 



QUERCUS RETICULATA Humboldt and Bonpland. 

 NETLEAF OAK. 



This oak, which is remarkable for its long-stalked acorns, was only 

 found on the San Luis, Animas, and Huachuca mountains. At the 

 summits of these high ranges it is a shrub, but lower down it becomes 

 a small tree with rough, whitish bark. On the west side of the San 

 Luis Mountains, in Turkey Canyon, it descends to 1,893 meters (6,210 

 feet). The largest tree seen was perhaps 20 feet in height and 6 

 inches in diameter ; but none were measured in the field. 



QUERCUS TOUMEYI Sargent. 

 TOUMEY OAK, 



This oak is about 8 to 10 meters (25 to 30 feet) in height,, with a 

 short trunk 15 to 20 dm. (6 to 8 inches) in diameter, usually dividing 

 near the ground into several stout wide-spreading branches, which 

 form a broad head. It occurs sparingly in the neighborhood of 

 Monument No. 40, in Grant County, New Mexico, and abundantly in 

 the Mule Mountains in Cochise County, in southern Arizona. It is a 

 tree of the Upper Sonoran Zone. 



