C. H. TYLER TOWNSEND-BIO-GEOGRAPHY OF TEXAS. 
81 
the region comprised between Orizaba, Perote, and Malintzi there is much 
of the Transition in the higher portions. It extends over the crests of 
the outlying spurs and ridges in most of the region around all the volca¬ 
noes above named. 
Other lower peaks to the west, in the lower southwestern limits of the 
plateau and mostly on the Pacific slope, all* over 10,000 feet, are Nevada 
de Colima (12,728 ft.), Patamban (12,290 ft.), Zampoaltepetl (12,100 
ft.), Ajusco (11,800 ft.), Colima (11,140 ft.), Quinceo (10,895 ft.), 
.Gigante (10,653 ft.), Las Llanitos (10,113 ft.), etc. These peaks I have 
not visited, but they have a well-marked Transition undoubtedly, together 
with a touch of the Boreal. Colima is stated to be snow-clad in winter, 
but not in summer. 
Texas. —The only Transition in this State is in the Guadalupe, Lim- 
pia, Chisos, and Eagle mountain ranges of Western Texas; on the higher 
ridges and bluffs of the Great Bend of the Rio Grande as far north as 
the Southern Pacific Railroad, on the forks of the Nueces river, and 
along the edges of the high plateau known as the Llano Estacado or 
Staked Plain. These touches of the Transition are borne out by the well 
marked occurrence of Pinus ponderosa , P. edulis , and Juniperus (exclu¬ 
sive of J. conjungens). Pinus ponderosa and P. flexilis occur in the 
Guadalupe and Limpia Mountains. P. edulis occupies the Chisos Moun¬ 
tains exclusively. The Boreal touches but one locality in the State, 
the heights of the Guadalupe Mountains, as attested by the presence of 
Pseudotsuga douglasii. There is only a faint touch of Transition on the 
Chinate Mountains, thin clumps of P. edulis occurring on their northern 
face. These statements are based on facts obtained from Havard (Proc. 
U. S. Nat. Museum, 1885, vol. 8, pp. 492 aDd 503). 
Guadalupe Peak, the highest in Texas, is about 900 feet above sea. 
Limpia Peak and the dome of the Chinates are 500 to 800 feet lower, and 
the Chisos Mountains are still lower. These mountains all lie west of the 
Pecos river, between the latter and the Rio Grande. 
UPPER SONORAN. 
New Mexico and Arizona. —Grand Canon and Gila Routes .—On the 
routes already described from Las Cruces, N. M., to the Grand Canon 
and return, and to the headwaters of the Gila and return, all portions 
not mentioned as Tt'ansition (or Boreal) are considered by me as Upper 
Sonoran, only excepting that within the Grand Canon of the Colorado 
river below 4500 feet. 
In a paper read before the New Mexico Society for the Advancement 
of Science, November 3, 1892, I provisionally referred to the portion of 
the Grand Canon, along the Hance trail, below the Transition , or in 
