114 BULLETIN 56, UNITED STATES NATIONAL MUSEUM. 



1392, when Lieutenants Gaillard and Irwin and the writer lay down 

 to rest upon the damp grass beside the San Bernadino Springs, 

 near Monuinfint Xo. 77. At dusk these huge green batrachians began 

 to hop about us, occasionally landing upon our faces. A few were 

 caught and saved as specimens. No more were seen by me until 

 October 3, 1893, when Hospital Steward E. 0. Merton brought me 

 another that he had just caught at a spring situated between Monu- 

 ment Xo. 78 and Cajon Bonito Creek, in Sonora, Mexico. Another 

 was taken at Quitobaquita Spring-. Monument Xo. 172, January 26, 

 18D4. 



Station No. 51. — LaVentana Ranch, Pima County, Arizona. This 

 place is about kilometers (5.5 miles) from Monument No. 146, 573 

 kilometers (356 miles) west of the Rio Grande, and 286 kilometers 

 (286 miles) east of the Colorado River. Altitude, 675 meters (2,215 

 feet). The region west of the Pozo Verde Mountains is a vast plain, 

 dry, but otherwise fertile, declining to the level of the Gulf of Cali- 

 fornia and Colorado River. This extensive area is strewn with desert 

 ranges of mountains, trending from northwest to southeast. Monu- 

 ment Xo. 146, on the Moreno Mountain (altitude, 1,420 meter-), 

 marks the western border of the Moreno Flat, which is bounded on 

 the east by the Baboquivari and Pozo Verde Mountains. This flat 

 is covered with grass and shrubbery, and is rich in animal and plant 

 life. In it we found groves of the long-leaved palo verde (Parkin- 

 sonia aculeata Linnseus). In traveling from La Osa to La Ventana 

 we found the first skeletons of the large land turtle, Gopherus agas- 

 sizii (Cooper), whose range extends to the Colorado River. 



Station Xo. 52. — Pozo de Luis, or el Vanori, Sonora, Mexico. 

 Station 8 kilometers (5 miles) south of Monument Xo. 152, 595 kilo- 

 meters (370 miles) west of the Rio Grande and 2G4 kilometer- ( L64 

 miles) east of the Colorado River. Altitude, 700 meters (2,300 feet ). 

 Camp Avas made at the Indian village, by the well of Yaqui Luis, at 

 the end of a valley at the west side of the Cobota Mountains, which 

 latter are 1,060 meters (3,478 feet) in altitude. The rock is granite, 

 uralite-diabase, rhyolite, and basalt. The Indians are mostly Papa- 

 gos, though there are a tew Yaquis, among them Luis, the owner of 

 the well. There is no cultivated land beyond a patch of an acre or 

 two beside and watered from the well. To the southwest is a plain 

 that rapidly declines to the coast level at the Gulf of California. 

 There was no bare ground in the neighborhood of this station, the 

 whole region being covered with shrubs and cacti, with trees along 

 the arroyos. Eronwood, mesquite, two species of palo verde, and tall 

 acacias formed a heavy growth along the principal arroyos. Creosote 

 bushes and cacti cover the higher flats, and the giant cereus and 

 ocotillo are abundant on the hills and mountains. ( Plate XII, fig. 2.) 

 On the southern slopes of the Cobota Mountains we met with the first 



