120 Part II. Chapter ı. 
other parts of Central America constituted a chain of Islands which have since 
been united by volcanic and meteoric agencies into a continuous landmass 
separating the oceans. The Central American igneous system is continued 
in the Panamaian highlands by the Cordillera de Chiriqui (11,850 feet), Rovalo 
7020 feet (2140 m), and Cordillera de Veragua. At Culebra Pass, 290 feet, the 
isthmus contracts to a width of about 34 miles and here the United States 
government is digging the isthmian canal. Several of the streams in Panama“ 
have a somewhat lenghty course in descending from the central uplands. 
Their basins are narrow and the volume of the streams is not great except 
during heavy rains, when they become swift and turbulent. Such is the Rio 
Chagres which flows through the canal strip and empties into the Atlantic 
near Colon, where its mouth is obstructed by a bar. Rio Bayano on the 
Pacific coast presents fewer obstacles to the engineers of the canal, because 
the western slopes of the country are drier. 
General remarks. — Central America and the West Indies including the 
Gulf of Mexico and the Caribbean Sea are largely individual in their aspects, 
although more nearly related to one another and to the northern coast of 
South America, than they are to the main bodies of the larger continents. 
The trends of the great North and South American mountain systems, 
the Rocky and Andean, if protracted would not connect with each other, but 
would pass nearly two thousand miles-apart. The Andean trends would pass 
through Jamaica and eastern Cuba and continue in the direction of Nova 
Scotia. A similar extension of the Rocky Mountains would carry ‚them into 
the Pacific far west of the South American continent. Between these two 
great systems of uplift occurs a third to which the name of Antillean may be 
applied. “East-and-west mountain ranges of the Antillean type occur through 
the great Antilles, along the Venezuelan and Columbian coast of -South 
America, south of the Orinoco; in the Isthmus of Panama, Costa Rica, and 
the eastern parts of Nicaragua, Guatemala, Honduras, Chiapas and southern 
Oaxaca. The two elongated submarine ridges, separated by the deep oceanic 
valley known as “Bartlett Deep”, which stretch across the Caribbean from 
the Antilles to the Central American coast, from the west end of the 
Sierra Maestra range of Cuba to the coast of Honduras, and from Jamaica to 
Cape Gracias a Dios respectively are similar in configuration to the east-and- 
west mountain ranges of the Greater Antilles, and are, no doubt, genetically a 
part of them’). The mountains and submarine banks described above form 
thus a perimeter-to the depressed Caribbean basin, which sank to great depths 
when the mountains were elevated. 
Central America, the West Indies and the northern margin of South America 
formed in the Mesozoic period (certainly during Jurassic and Cretaceous) a 
continental mass (Antillean continent), which was bounded by sea to the north 
ı) HıLL, ROBERT T.: Cuba and Porto Rico with the other Islands of the West Indies. 
p- 4. 1898. 
