VIEWS OF Mil. GUPPY, 
291 
Mr. Guppy 1 describes the Solomon Archipelago, which 
includes seven or eight large islands, some being from 
seventy to eighty miles in length, and the highest rising 
from 8,000 to 10,000 feet above the sea, with a great 
number of smaller islands and islets, some of volcanic and 
others of recent calcareous formations. The author found 
exploration to be difficult and dangerous, but believes that 
he saw enough to give him a fair idea of the leading types 
of structure among these islands. The observations re- 
corded in the paper may be summed up in his own 
words : — 
The islands examined indicate upheaval, in some cases 
to at least 1,200 feet. ‘There are, in the first place, 
numerous small islands and islets, less than a hundred 
feet in height, which are composed entirely of coral lime- 
stone. Then there are islands of larger size, which are 
composed in bulk of partially consolidated volcanic muds, 
such as are at present forming around oceanic volcanic 
islands. Coral limestones encrust the lower slopes of 
these islands, and do not attain a greater thickness than 
150 feet. In the next place we have islands of similar 
structure, but possessing in their centre some ancient 
volcanic peak that was once submerged. Then there are 
observed by Agassiz in the region in the Keys must be of very 
limited scope, as it has not been identified from the mainland of 
Florida by any modern geologist.’ Further, Prof. A. Heilprin in a 
paper on Explorations in Florida (Transactions Wagner Inst. Sci. 
Philadelphia, May 1887), noticed in the above-named volume (p. 230), 
says: 1 No observed facts sustain the coral theory of formation pro- 
pounded by Agassiz. They prove, on the contrary, that the coral 
tract of Florida is confined to a border region on the south and 
south-east, and there are no tertiary reefs whatever.’ But he admits 
that the southern area is one of shallow sea formation, so that there 
has been a gradual uniform progressive elevation over the whole. 
1 H. B. Guppy. Observations on the Becent Calcareous Forma- 
tions of the Solomon Group made during 1882-4. Tr. R. S. Edin, 
xxxii. p. 545 (1884-5). 
