HILL: GEOLOGY OF THE ISTHMUS OF PANAMA. 217 
projecting away from the point show the same topographic forms as the 
mainland, and it is clear that they have been severed from it. 
From Mariato Point to Matapalo Head, the latter marking the ex- 
tremity of the peninsula which encloses the Gulf of Dulce, the arrange- 
ment and topography of the numerous islets present additional evidence 
that in this region an immense stretch of the mainland has been eroded 
by the Pacific; the islands remain as monumental evidence of this decay, 
being geologically and topographically identical with the mainland. 
Our steamer strikes out due west from Mariato Point to Jicarita 
Island, the southernmost of the Coiba group. 
A glance at Jicaron and Jicarita islands shows that they have clearly 
once been connected with each other, and more remotely with the 
mainland. They have the same identical coast characteristics as the 
Fiaure 17. Coast Topography between Mariato Point and Moro Puercos. 
islands of Panama Bay and Mariato Point, and likewise above this they 
show the older peneplain topography.  Jicaron is dominated by a three- 
cusped mountain in its centre, identical in topographio aspect with many 
of the summits of the Isthmian mainland. A small remnantal rock 
stands a few feet from the main shore, rising to the height of the wave- 
cut terraces, and apparently having been but recently separated by wave 
action. Above the wave-cut coast bluff of the larger islands there is a 
rapid slope of erosion ascending to the peneplain level. Тһе rock of 
these islands appears to be a white andesitic looking material. 
We get a distant view of the large island of Coiba sufficient to show 
that it is of the same type of denuded mainland topography which we 
have described. Here can clearly be seen the wave-cut cliffs, the Panama 
peneplain and low summits similar to those of the Isthmian topography. 
From the passage between Jicarita and Jicaron the vessel strikes for 
Cape Matapalo, and land is temporarily lost to view. The steamer did 
not enter the Gulf of Dulce, but kept close to the shore line of the bor- 
dering peninsula. The same wave-washed cliff lines are visible off Cape 
Matapalo, the coast and the stretch of.low peneplain extending inland 
from it to the mountainous masses of the interior. 
