42 BOTANICAL FEATURES OF NORTH AMERICAN DESERTS. 
with a felt composed of two alge, Phormidium tenue and P. tenuissimum, 
both of which are identical with or nearly related to forms in the Hot 
Springs of Yellowstone Park. The water of the spring was also inhabited 
by a small rain-water fish. Specimens of this were submitted to Dr. 
D. S. Jordan, of Stanford University, who found that it belonged to a 
hitherto unknown species; and it was given the name of Lucania brownit, 
in honor of Mr. Herbert Brown, a member of the expedition. A dozen 
of these fish, taken from the spring, were placed in a vessel of water which 
cooled to air temperatures during the day and the following night with- 
out apparent discomfort to the animals. The water of the spring itself 
is highly charged with several salts, of which chloride of lime is one of the 
most abundant. It is to be seen, therefore, that this fish not only endures 
a water highly charged with salts, but is also capable of accommodating 
itself to great range of temperature. The entire spring is submerged to a 
depth of a half foot by the waters of the laguna at flood. 
THE SAN FELIPE DESERT IN BAJA CALIFORNIA. 
The western shore of the Gulf of California is made up of a continua- 
tion of mud flats and saline plains for some distance south of the 
mouth of the Colorado River. South of this formation the gravelly 
slopes and granite and volcanic ridges of the mountains come out to the 
shores, and here, to the leeward of the main ridge of the peninsula, are 
to be found some of the most arid conditions in North America (plate 45). 
The central elevation consists of the mountain ridge which culminates 
in the peak of Calamahuie at an elevation estimated at 10,000 feet. To 
the eastward it breaks into lofty precipices and steep slopes which have 
not been surmounted between 30° 30’ and 32° 30’ N. 
The lower coastal slopes are sandy and gravelly, the depressions and 
dunes near the shore furnishing suitable conditions for Lycium torreyt 
(plate 47) and Parosela spinosa, which latter becomes a tree 25 feet in 
height. Ascelepias subulata was abundant in clumps, and Ditaxis serrata 
grew on level areas. Other species which were characteristic of the 
lower levels were [bervillea sp., Croton caltfornicum, Lupinus mexicanus, and 
the curious Frankema palmert. The low alkaline pockets reached by the 
spring tides furnished conditions suitable for Spzrostachys occidentalis. 
Covillea, with its enormous capacity of adjustment, extended from near 
the shore across the entire slope and up the granite mountains through 
a range of over 2,000 feet in elevation. The various portions of the 
slope between the sea and the first range of coastal mountains supported 
ocotillo (Fouqumeria splendens), which attained its maximum height of 
30 feet, palo verde (Parkinsonmia microphylla), palo fierro (Olneya tesota), 
and Gaertneria tlicifolia. On an expedition to this place in 1904 a new 
copal tree was found, Terebinthus macdougali (plate 46), which also is now 
known to occur on the eastern shore of the Gulf, and which secretes a 
