122 BULLETIN- 56, UNITED STATES NATIONAL MUSEUM. 



This description points to the chuck-walla (Sauromalus ater Du- 

 meril) , as the alleged gila monster of this region. 

 • In April, 1893, Mr. Wheeler found, in the Tule Mountains, a few 

 horned toads and also snakes resembling the coach- whip, which were 

 yellowish with dark stripes across the body and about 4 to 6 feet. He 

 also found rattlesnakes {Crotalus tlgris Kennicott) averaging 18 to 

 24 inches in length, light brown in color, Avith stripes across the body, 

 and three to eight rattles. The head was rather large in proportion. 



Station No. 62. — Eange of Granite Mountains, about 6 kilometers 

 (3^ miles) north of Monument No. 187, 766 kilometers (476 miles) 

 west of the Rio Grande, and 93 kilometers (58 miles) east of the Col- 

 orado River; altitude about 325 meters (1,060 feet). The writer, 

 who discovered a small tank of water in a canyon of these mountains, 

 trapped mammals and collected birds and plants February 10 and* 

 12 to 14, 1894. 



. Station No. 63. — Tinajas Altas, Yuma County, Arizona, 8 kilo- 

 meters (5 miles) north of Monument No. 191; 789 kilometers (490 

 miles) west of the Rio Grande, and 70 kilometers (44 miles) east of 

 the Colorado River. Altitude, 335 meters (1,099 feet). This im- 

 portant station is at the east base of the Gila Mountains, beside the 

 lowest of a chain of natural rock tanks, in a steep ravine, containing 

 an unfailing and almost inexhaustible supply of good water. (Plate 

 XIII, fig. 1.) The upper tanks are easily overlooked and difficult 

 of access, which facts afford the most plausible explanation of the 

 loss of the lives of many persons whose bones and graves were thickly 

 scattered about our camp. The Gila Mountains reach the altitude 

 of 861 meters (2,825 feet), and are remarkably rocky, with crests so 

 sharp that it is impossible to walk along their summits. The rock 

 is a coarse granite. Around the base of these mountains the last of 

 the giant cereus were found, on the Boundary Line. One species of 

 palo verde, the small-leaf horse bean, and the ironwood, indigo, 

 thorn, acacia, mesquite, and nolina complete the list of trees, which 

 are mostly confined to arroyos around the base of the mountains. 

 Species of Lotus, Agave, Cotyledon, Fouqideria, Cooillea, Ephedra, 

 Datura, Nicotiana, TereUnthus, Gvmrlita, Euphorlia, and Physalis 

 were common. Of cacti, a species of Cylindropuntia, called " tasajo," 

 and another resembling the choya, one small species of Platopuntia 

 that we only saw on the mountains of the Western Desert, a small, 

 long-spined Cereus, the handsome, red-spined Echimcactus lecontei, 

 and several species of the genus Cactus were the common sorts. 

 Gerem greggii and one or two other cacti were found more spar- 

 ingly. Collections in botany and zoology were made by the writer 

 and his assistant from February 14 to 23, 1894, during which time a 

 line of mammal traps were carried from the middle of the liechu- 

 guilla Desert on the east to the summit of the Gila Mountains. 



