THE GALAPAGOS AECHIPELAGO. 267 



Subjoined is a table of the various islands, arranged in order of size, and witt 



their respective English and Spanish names. 



Albemarle ; Isabella. Bindloe ; Marcbena ; Torres. 



Indefatigable ; Infatiguable ; Tierra de Valdez ; Abingdon ; Pinta ; Geraldino. 



Duke of Norfolk ; Santa Cruz ; Santiago. Tower ; Genovesa. 



Narborough ; Fernandina. Culpeper ; Jervis ; Rabida ; Guerra. 



James ; Santiago ; San Salvador ; Tierra de Gil. "Wenman ; Nunez ; Gasna. 



Chatham ; Grande ; San Cristobal. Barrington ; Santa Fe. 



Charles ; Mascarin ; Floreana ; Santa Maria. Duncan ; Pinzon. 



Hood ; Espanola. Islote Redondo ; Roca Redonda. 



The archipelago has a collective area of 3,000 square miles, with a settled 

 population (1892) of 232, concentrated in Chatham Island. 



From the easternmost reef of the archipelago to the coast of Ecuador the 

 total distance is 574 miles, and the mean oceanic depth exceeds 1,250 fathoms, 

 the greatest cavit}'' revealed by the soundings of the Albatross being 1,675 fathoms 

 deep. The islands are disposed in two groups, each resting on a pedestal of 

 1,000 fathoms. The isobathmic curve of 1,500 fathoms is developed along a 

 submarine bank, which is prolonged north-eastwards under Cocos Island, tapering 

 thence to a point turned towards the Azuero peninsula in the region of the 

 isthmuses. Hence, if they are to be regarded as a geological dependency of the 

 New World, the Galapagos Islands must be attached, not to South but to Central 

 America, although still separated even from this region by depths of 1,500 

 fathoms. 



VohCA^io Formation. 



But whatever be the origin of these oceanic lands, whether upheaved from 

 the abysses of the ocean or the remains of some vanished continent, they have 

 certainly been isolated from the rest of dry land since remote geological times. 

 All are entirely composed of volcanic rocks, presenting little beyond molten lavas, 

 obsidians, dolerites, basalts and other erupted matter of various ages. In the 

 gorges of the volcanoes there, no doubt, occur here and there a few fragments of 

 vitrified granite, but these were evidently torn from the marine bed and thrust 

 upwards during the eruptions. 



To judge from the disposition of the groups, the sea-bed would appear to have 

 been rent by two systems of fractures crossing each other at right angles. The 

 most numerous fissures run in the direction from south-east to north-west, parallel 

 with the submarine plateau dominated by Cocos Island, and in a line with the 

 igneous chains of Costa Hica and Nicaragua in Central America. This system is 

 intersected by the second, which is disposed north-east and south-west parallel 

 with the Eastern Cordillera of the Colombian Andes. 



The large island of Albemarle consists of volcanic ridges belonging to both 

 systems, the larger section rising parallel with Central America at right angles 

 with the two smaller chains in the extreme north and south. A general upheaval 

 of the archipelago would give a length of 300 miles to an elongated island trending 

 south-east and north-west from Hood to Culpeper. 



All volcanic life has ceased everywhere, except in the two western islands of 



