10 BULLETIN 56, UNITED STATES NATIONAL MUSEUM. 



ones of Kceberlinia, Ephedra, and "ocotillo; " and Perezia, with its 

 papery spinulose-dentate leaves grew abundantly in the shelter of 

 shrubs, associated with a curious gourd, Ibervillea lindheimeri (Cog- 

 niaux) Greene. Cacti were not numerous, though several kinds were 

 found sparsely, and prickly-pears were common in a few places. The 

 gold fern was abundant on rocky buttes in the vicinity of Monument 

 No. 15. 



About 47 kilometers (29 miles) west of the Rio Grande the first 

 hill of considerable size was reached. Forty-eight kilometers (30 

 miles) from the initial monument is a depressed, oblongated basin, 

 in which are several lava buttes. where we gathered specimens of vol- 

 canic scoria (basaltic lava) varying in color from red to black and 

 gray. This spot was indescribably rough, dismal, and forbidding. 

 Near Monument No. 11 we reached a number of volcanic buttes and 

 low hills called Sierra Seca, the country being everywhere strewn 

 with scoriaceous basalt and other effusive rock. We continued 

 through a similar country to Monument No. 15. about 80 kilometers 

 (50 miles) west of the Rio Grande, in the midst of the Seca and 

 Aguila mountains. 



March 20 t<> April 7, 1892. — In camp near Monument No. 15, dis- 

 tant 80 kilometers, or 40.0 miles, from the Rio Grande. 



April 7 to 15, 1892. — Moved to Monument No. 21, near Columbus, 

 New Mexico, on April 7, remaining there until April 15. During 

 this time daily visits. were made, either by Mr. Holzner or myself, to 

 Lake Palomas, in the Mimbres Valley, 5 miles southwest of our cam]), 

 in Chihuahua, Mexico. Our camp was a short distance south of the 

 Boundary Line. 



Between Monuments Nos. 15 and 24 there are no ledges of rock. 

 The low hills and cliffs southwest of Monument No. 23 (about 0.7 kilo- 

 meters or (') miles west of Lake Palomas) are of dark-brown augite- 

 andesite, a kind of effusive rock which was abundant as " float " in 

 this neighborhood, but was not again found until we reached the 

 shores of the Pacific Ocean and San Clemente Island. In the higher 

 hills of this locality much of the rock is rhyolite. In the broad plain 

 between Monuments Nos. 26 and 31 are outcroppings of rhyolite of a 

 light-gray porphyritic variety. 



April 15 to 22, 1892. — On April 15 moved from near Monument 

 No. 21 to near Carrizalillo Springs and Monument No. 33, camping 

 on the New Mexican side of the Boundary until April 22. Collections 

 were made principally in the Carrizalillo Mountains. At that time 

 many of the earliest plants were beginning to flower. 



April 22 to May 15, 1892. — Moved April 22 from near Monument 

 No. 33 to the " Upper Corner" or Monument No. 40, at the west end 

 of the second section of the Boundary Line formed by the parallel 

 31° 47' north latitude, and camped there until May 15, exploring 



