Stewart—Botanical Conditions fin the Galapagos Islands, 279 
There are also two other tufa craters in this vicinity. The 
smaller one of these is located just north of the cove and con¬ 
tains a miniature salt-water lake, while the larger is situated 
about a mile south near the coast. This third crater has prob¬ 
ably formed a small bay some time in the past, as its walls are 
broken down on the side next to the sea, similar in this respect 
to the crater that forms Tagus Cove. The opening has been 
closed, however, by a flow of lava across it, and is now filled with 
salt water which comes in through the cracks in the lava from 
the sea a short distance away. There are four islets in this lake, 
one of which has a small crater on it. It is evident from the de¬ 
scription, given by Darwin in his Voyage of the Beagle, that this 
is the salt water lake that he describes as being located near 
“Banks Cove”. The sides of all these craters are much cut up 
by gullies which have been eroded in them. All three of the 
tufa craters just described, are separated from the base of the 
mountain by a plain, about one and a half miles wide, which is 
covered with deposits of volcanic cinder northeast of the cove. 
These cinder deposits extend along the base of the mountain 
northward and are continuous with the lava beds in the Banks 
Bay region. The cinder beds do not extend south of Tagus 
Cove, however, as the country around the base of the mountain 
in this direction, is covered with deposits of tufa, which extend 
out to the coast and form cliffs 40-50 ft. high. 
The mountain lies northeast of the cove and is the second one 
of the three mountains that make up the northern part of the is¬ 
land. The mountain at Banks Bay is the one furtherest north, 
and the one at Cowley Bay furtherest south in the chain. The 
west side of the mountain, opposite the cove, is rather steep to 
an elevation of 2,500 ft. There are extensive deposits of tufa be¬ 
low this elevation, in which deep canyons have been eroded, and 
small gullies are common everywhere. There are two flows of 
comparatively recent lava, covering the tufa, and extending 
down the side of the mountain. They have evidently originated 
from small craters near an elevation of 2,500 ft. Deep fissures 
occur in these beds in places. The side of the mountain is covered 
with extensive deposits of partly disintegrated lava, above an 
elevaton of 2,500 ft., which is similar but much older than the 
lava which has formed the flows down the side below this eleva¬ 
tion. The north side of the mountain seems to be entirely cov¬ 
ered with lava. 
