678 The American Naturalist. [August, 
tuffs and conglomerates are often fossiliferous, and form the 
superficial cover. These fossils are of Tertiary age, and cer- © 
tainly not older than Miocene. Of minerals: gold, copper, 
quartz, pyrite, heematite and others were found. All the other 
islands visited by Kleinschmidt, Kandavu, Ovalau, Ono, Vatu 
Lele and the Munia, Kanathia, Vanuna- palati of the Explor- 
ing Islands, on which Gräffe collected, consist nearly entirely 
of Andesites and Basalts and their tuffs. In some, for instance, 
Ono, Vatu Lele, coral-rocks and silicified corals occur. 
If we compare the results found on the Fiji Islands with the — 
geological conditions of other islands of the Pacific Ocean, we 
partly observe very surprising similarity. A very short time 
ago it was considered as certain, and generally accepted, that 
all islands of the Pacific Ocean originated through volcanic 
activity. As exceptions were named New Zealand and New Cale- 
donia. The investigations of the last years have brought for- 
ward more light about several of these conditions. Drasche, 
in 1879 (Neues Jahrb. Min. Geol., 1879, p. 265), stated that only 
those groups of islands placed eastwards from a line extending 
from Kamtschatka over Japan, the Philippines, New Guinea, 
New Caledonia, New Zealand, Auckland, Macquarie to Arctic 
Victoria, are either coral islands, or consist of young volcanic 
rocks. 
Outside of this line there are, besides the Fiji Islands, some 
other groups. From the Pelew Islands Wichmann described 
large blocks of a very coarse-grained hornblende-granite and 
diabase, found at the seashore and at elevations of 400 m. 
[Journal des Museum Godeffroy, 1875, VIII, p. 126.] Mar- 
cou has reported granite and gneiss from the Marquesas Islands, 
and Eichwald” has shown that the Aleutian Islands contain 
Cretaceous strata. 
Wichmann makes the following remarks at the end of his 
paper: “No older massive rocks or sedimentary strata are 
known from the other “ volcanic” groups of islands of the 
Pacific Ocean, and on some of these, for example, the Galápa- 
pos or Sandwich Islands, it seems really to be made out that 
3 Eichwald, E. Geognostisch-palentologische Bemerkungen über die Hal- 
binsel Magischlak und die Aleutischen Inseln. St. Petersburg, 1871. 
