Vor. I] STEWART—BOTANY OF THE GALAPAGOS ISLANDS 109 
and uneroded as when first cooled, and it is usually in such 
situations that it is the most abundant. The branches of this* 
species radiate upward and outward to a height of 2-3 ft., form- 
ing candelabra-like masses. The cactus with the habit of C. 
peruvianus, mentioned by Henslow, Mag. Zool. and Bot. 476 
(1837), probably belongs to this species. Plate V. Endemic. 
C. sclerocarpus K. Sch. in Rob. (1), 179.—A.pBemarte Ist. : 
Banks Bay, an arborescent species of Cereus was reported from 
this place by F. X. Williams; it most likely belongs to this 
species ; Black Bight, Snodgrass and Heller; Christopher Point, 
Snodgrass and Heller. It was noticed, in sailing by this por- 
tion of the island, that this species grows very abundantly on 
the barren lava fields near the coast; Tagus Cove, occasional 
on cinder beds in the vicinity of the cove and at various places 
on the side of the mountain. It also occurs fairly abundantly 
on the floor of the crater at about 3600 ft., where the conditions 
are desert in the extreme; Villamil, in barren rocky places in 
the vicinity of the shore, and in similar situations around the 
base of the mountain to 100 ft. A few specimens were noticed 
on the inside of the crater at 2750 ft., along with other xero- 
phytic plants, (no. 2095). InpEFaTicaBLe Ist.: Academy 
Bay, abundant in dry rocky places near the coast, seldom 
occurring any distance inland, (no. 2096). James Ist.: 
James Bay, abundant on recent lava flows to 900 ft. south of 
the bay. It occurs most abundantly along the edges of the 
flows, but stops abruptly as soon as other large vegetation 
begins to appear, (no. 2097). Narsoroucu Ist.: south side, 
a species of Cereus was reported by J. S. Hunter from this side 
of the island. It was probably this species. 
This species can be distinguished from C. galapagensis by 
the following characters: branches few and usually parallel; 
articulations usually elongated, somewhat slender, 15-angled. 
All of the flowers secured were smaller than those described by 
Schumann, op. c. 180. The great variability in the flowers of 
this species is well illustrated by two flowers taken from the 
same plant on Indefatigable Isl. One of these has most of the 
petals broadly spatulate, truncate, and slightly emarginate, 
while the other has them mostly narrowly oblong and rounded. 
All of the species of Cereus which grow on these islands are 
found only in the most open and desert situations. One may 
