MAMMALS or THE MEXICAN BOUNDARY. 



97 



326 kilometers (202 miles). A hilly region, covered with volcanic 

 scoria, sparsely clothed with grass and brushwood, with a few red 

 juniper trees. Within a radius of a dozen kilometers (7 miles) a 

 range of altitude from 1,200 to 1,640 kilometers (3,940 to 5,380 feet) 

 could be found. Station occupied by myself September 1 and 11, 

 1892 ; August 14 to 17 ; and October 7, 1893. Plants, birds, etc., were 

 collected. 



Flora of Cerro Gallardo. — The trees and plants obtained near this 

 station are named in the following lists. 



The trees are : 

 Juniperus monospernia ( Engelmann ) 



Sargent. 

 Yucca brevifolia Torrey. 

 Salix taxifolia Humboldt, Bonpland, 



and Kunth. 

 Quercus a/rizonica Sargent. 

 Geltis reticulata Torrey. 

 Morns oeltidifoUa Humboldt, Bon- 

 pland, and Kunth. 

 Platanus lerightU VPatson. 



Acacia constricta Bentham. 

 Acacia greggii Gray. 

 Prosopia sp. 



Eysenhardtia orthocarpa (Gray) Wat- 

 son. 

 Kwierlinia spinosa Zuccarini. 

 Sapindus marginatus Willdenow. 

 Bumelia rigida (Gray) Small. 

 Fraasinus velutina Torrey. 



Other shrubs and conspicuous plants are : 



Ephedra trifurca Torrey. 



Yucca iaccata Torrey. 



NoUna UndJieimeriana (Scheele) Wat- 

 son. 



Dasylirion wheeleri Watson. 



Agave palmeri Engelmann. 



GucurMta fwtidissima Humboldt, Bon- 

 pland, and Kunth. 



Gucuriita digitata Gray. 



Apodanthera undulata Gray. 



Mimosa hiuncifera Bentham. 



Mimosa Undheimeri Gray. 



Mimosa dysooarpa Bentham. 



Tre- 



Mimosa grahami Gray. 



Acacia filiculoides (Cavanilles) 



lease. 

 Cassia wislizeni Gray. 

 Erythrina flabeUiformis Kearney. 

 Krameria parvifoUa Bentham. 

 Fouquieria splendens Engelmann. 

 Covillea tridentata (de Candolle) 



Vail. 

 Rhus virens Lindheimer. 

 Opuntia of subgenera Platopuntia and 



Gylindropuntia. 

 Baccharis glutinosa Persoon. 



Station No. 28. — Agua Prieta Eanch, Piedras Negras, Sulphur 

 Spring Valley. Monument No. 85, distant from the Rio Grande 

 338 kilometers (210 miles). Altitude, 1,204 meters (3,950 feet). 

 Occupied by myself September 11 and 12, 1892 ; August 14 ; and Octo- 

 ber 7, 1893 ; by Mr. Holzner, September 11 to 12, 1892. This broad 

 valley, though crossed several times, was not carefully examined, and 

 the collections made were small. 



Vegetation. — The ground is part bare and part grassy, with exten- 

 sive patches of the gregarious creosote bush {Covillea tridentata), 

 and considerable greasewood (Atriplex) , with some cacti. Soapweed 

 (Tucca glauca) and a narrow-leaved yucca having a long caudex 

 were sometimes seen; and some superb hackberry trees formed a 

 grove on an arroyo at the west side of Sulphur Spring Valley, at 

 30639— No. 56—07 m 7 



