Its 
THE TS7.ASD OF OllCUILA. 
be augmented by their presence, especirlly between 28* 
and 30“ of nortii latitude, which indicates an origin of some 
sort of animal nature. 
On the 27th, wo slowly approached the island of Orehila. 
Like all tlie small islands in the vicinity of the fertile coast 
of the continent, it has never been inliabited. I found the 
latitude of the northern ca])e, 11° 51' 4# and the longitude 
of the eastern cape, 68° 26' 5" (supposing Nueva Barcelona 
to be 67° 4' 48'). Opposite the western cape there is a 
small rock against which the waves beat turbulentlv. Some 
angles taken with the se.xtant, gave, for the length of the 
island from east to west, 8 4 miles (950 toises) ; and for the 
breadth scarcely three miles. The island of Orclnla, which, 
from its name, I figured to myself as a bare rock covered 
with lichens, was at that period beautifully verdant. The 
hills of gneiss were covered with grasses. It appears that 
the geological constitution of Orcliila resembles, on a small 
scale, that of Margiierita. It consists of two groups ot 
rocks joined by a neck of land ; it is an isthmus covered 
with sand, which seems to have issued from tlie floods by 
the .successive lowering of the level of the sea. The rocks, 
like all those which are perpendicular and insulated in the 
middle of the sea, appear much more elevated than they 
really are, for they scarcely e.vceed from 80 to 90 toises. 
'fhe -Pii/ita rasa stretches to the north-west, and is lost, 
like a sandbank, below the waters. It is dangerous for 
navigators, and so is likewise the Mogote, which, at the 
distance of two miles from the western cape, is surrounded 
by breakers. On a very near examination of these rocks, 
we saw the strata of gneiss inclined towards the north- 
west, and crossed by thick layers of quartz, 'fhe destuction 
of these layers has doubtless created the sands of the 
surrounding beach. Some clumps of trees shade the valleys, 
the summits of the hills are crowned with fan-leaved palm- 
trees ; probably the palma do sombrero of the Llanos 
(Corypha tectorum). Bain is not abundant in these coun- 
tries ; but probably_ some springs might be found on the 
i.shind of Orehila, if sought for with the same care as in 
the mica-slate rocks of Punta Araya. When we j jcollect 
how many bare and rocky islands' are inhabited and culti- 
'ated between the I7th and 26th degieea of la'-'iude in the 
