1885.] PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 497 



Vol. VII §, No. 33. Washington, D. C. S«^tr^S, 1885. 



aius and Sierra Pesimo tie Caballo. It may be described as a sandy 

 basin, ybout 50 miles long and from 15 to 20 miles wide, through the 

 center of which stretches a chain of salt lakes, some not larger than 

 ponds, others several miles long. The water is clear but quite brackish, 

 and seldom drinkable even for animals. In a few places, however, near 

 the edge of some of the lakes, springs are found with good water. Large 

 deposits of chloride of sodium occur in places. Between Crow Spring 

 and Guadalupe Peak, is a range of white sand-hills whose shifting, 

 glistening surface is delicately undulated by the wind. 



The smooth, broad beach of the lakes, more or less iucrusted with 

 alkali, is absolutely bare. Here and there, low sand hillocks are cov- 

 ered with iSpirostachf/s occidentalism Larrea 3Iexicana, and Frankenia 

 Jamesii. Along the edge of the basin, the broken, gravelly ridges bear 

 a fair amount of Grama, and afford refuge to the narrow-leaved Yucca, 

 Bear-Grass, and Maguey {Agave Wislizeni). 



Crow Spring, an appropriate name, suggestive of the only bird inhab- 

 iting this region, lies near the northern extremity of the basin, on the 

 road to El Paso. The only ligneous vegetation visible here is a thicket 

 of Forestiera NeoMexicana. The water is brackish and the grass salt, 

 the latter consisting mostly of Sporobolus airoides and Wrightii. 



PART II. 



ECONOMIC NOTES ON THE TEXANO-MEXICAN FLORA. 



The plants herein noticed are grouped together in their natural 

 botanical orders and genera, while 'the orders succeed one another some- 

 what as convenience and usefulness suggested. 



LEGUMINOS^. 



Prosopis juliflora, DC. (Algarobia glandulosa). (Mezquit.)* 



This tree constitutes the principal growth of the wooded table-lands and 

 high valleys throughout South and Southwestern Texas. The trunk is 

 seldom over a foot in diameter and generally too crooked and knotty to 

 make serviceable lumber. Mezquit posts and rails, much used in fenc- 

 ing, are but slightly affected by exposure to ordinary weather influences, 

 and if care be taken to strip off the bark so that the eggs of the Mez- 



* The correct spelling of this Mexican name is Mezquite, with the accent on the 

 penult imate. North of the Rio Grande the final e is generally omitted, but the accent 

 should remain the same and the word be pronounced as if written ' Mezkeet'. 



For fuller details see American Naturalist for May, 1884. 

 Proc. Nat. Mus. 85 32 



