282 Field Columbian Museum — Zoology, Vol. III. 



New forms of Citellus, Dipodomys, and Perognathus were procured 

 here, and also topotypes of Thomomys operarius and Di podomys m. 

 nitratus. From this last stopping-place Mr. Heller drove to Fort 

 Tejon, which journey occupied nine days, and a week was passed 

 at this place. Mr. Heller writes : "Fort Tejon lies in the San Joaquin 

 drainage, a few hundred feet below the divide between the Mohave 

 Desert and the San Joaquin Valley. North of the P'ort the Teha- 

 chapi Range rises gradually northward and culminates in Tehachapi 

 Peak. At their southern end near the Fort, their sides are gently 

 rounded and the summits broad and level. To the south of the 

 Fort, Mt. Pinos rises abruptly to a height of nearly 10,000 feet. On 

 this mountain three new forms belonging to the genera Peromyscus, 

 Ncotoma and Perognathus were procured. Three drainage systems 

 center about Mt. Pinos; those of the north and west slope into the 

 San Joaquin Valley; those of the east and south go toward the coast, 

 and that of the east of the slopes of the Tehachapi and Libra Ranges, 

 passes into the Mohave Desert. The west, or rather northwest, 

 slope of the pass drops away much more rapidly than the east, which 

 drops about 500 feet in ten miles, where it merges into Antelope 

 Valley. 



The rock formation is largely shale, sandstone, or limestone. The 

 hills down to an altitude of 2,000 feet are heavily covered with 

 chaparral of scrub-oak, buck-thorn, chamiso, manzanita, Garrya, and 

 other shrubs. In the canons and ravines several kinds of oaks pre- 

 dominate. The hills above 4,000 feet are covered by a scattered 

 forest of pifion pines, which give way to the black pine at 6,000 feet. 

 The desert slope of the hills is similar in vegetation to that of the 

 coast, but supports a scattered growth of gray pines below the Pihon 

 Zone. The lower slopes of hills bordering the San Joaquin Valley 

 are largely clothed by buckeyes, poison-oak, box-elder, cottonwoods, 

 willows, and Isomeris brush. The valleys among the hills are usually 

 open and grassy below 5,000 feet, with a widely scattered growth 

 of California white oak. Above 5,000 feet many of the valleys are 

 choked with sage-brush and scrub-oaks. 



Three days were passed at the mouth of the Canada De Las 

 Uyas, between the Fort and Rose Station, on the edge of the San 

 Joaquin Valley, and topotypes of Antrozous p. pacificus were pro- 

 cured. Five days were passed at Castac Lake, and then Lock- 

 wood Valley was visited. This Valley lies "broad and open at the 

 east base of Mt. Pinos, at an elevation of 5,000 feet. The drainage 

 is southeast into Piru Creek. The valley is chiefly a sage-brush 

 plain, and the hills surrounding it are forested with Piiius mono- 



