740 
Darwin, C., thickness of reefs, 47. 
soundings near coral islands, 55. 
depth of water at Keeling Island, and 
on coral mud of, 63. 
on the Maldives, 66, 133. 
depth of growing corals, 98. 
on the origin of coral mud, 108. 
theory of coral islands, 125. 
observation on the summit of Cotopaxi, 
356. 
rarity of dislocations in volcanic dis- 
tricts, 361. 
on the cause of feldspathic centres of 
volcanic mountains, 374. 
arrangement of the Galapagos Islands, 
418. 
origin of valleys of Australia, 527. 
views of, on elevation of San Lorenzo, 
591. 
on the Patagonian tertiary, 609. 
Dean’s Island, 48, 54. 
elevation of, 402. 
Deception Island, remarks on, 547. 
Declivity, see Slope. 
Decomposition of basaltic rocks, in Austra- 
lia, 518. 
producing a material like 
mica slate, 515. 
on Tahiti, 298. 
of rocks of Nassau Bay, 606. 
of rocks of New Zealand, 441. 
of granite, Chili, 578. 
of Wollongong sandstone, 400. 
Degradation from the action of the sea, 111, 
381. 
from running waters, 384, 386. 
evidence of the length of time since 
volcanic eruptions ceased, 283, 391. 
Degradation in Feejees, 350. 
of rocks, New South Wales, 526. 
in Oregon, 670. 
Delta of Feejee rivers, 340, 
Depeyster’s Island, 407. 
Depths of growing corals, 98. 
Descloiseaux, A., temperature of geysers, 
203. 
Deserts, cause of, 455. 
INDEX. 
Dibble, J., an early eruption of Kilauea, 183. 
Dieffenbach, on New Zealand, 487, 447. 
Dikes, effects of, on forms of volcanic cones, 
360, 361. 
regularity of, in volcanic regions, 361. 
of Chili, 582. 
of Kauai, 269. 
of Madeira, 552. 
of Nassau Bay, 605. 
of basalt, New South Wales, 505. 
at Punch-bowl, Oahu, 243. 
near Kaala, Oahu, 251. 
of Tahiti, 297. 
of Upolu, 317. 
of sandstone, in Oregon, 654. 
Dislocations, a result of contraction, 430, 
rare, in volcanic districts, 361, 436. 
Distribution, geographical, of coral reefs, 
134, 
Dolomite, origin of, 153, 731. 
Donax ? protexta, 723. 
Douglas, height of Mounts Loa and Kea, 
156, 157. 
on Kilauea, in 1834, 187. 
ascent of Mount Loa, 208. 
Drift sand-rock of coral material, 45, 64,277. 
Drummond Island, 409. 
Ducie’s Island, elevation of, 403. 
Duke of York’s Island, 72, 407. 
Duke of Clarence, 54, 407. 
Duchassaing, on the rate of growth of a 
Madrepore at Guadaloupe, 102. 
Earth, origin of general features of, 424. 
structure of crust of, 421, 435. 
Earth’s crust, thickness of, according to W. 
Hopkins, 427. 
Earthquakes, a cause of, 432, 436. 
none at an eruption of Kilauea, 188. 
ibid. of Mount Loa at summit, 210. 
of Valdivia, in 1837, causing waves 
on Pacific Islands, 27, 3385. 
rotation by, in Lima, Peru, 599, 
Kast Indies, curved ranges in, 419. 
coral reefs of, 142. 
Philippine and Sooloo Islands, 539. 
Eimeo, 285, 302. 
