Geology and Natural History. 235 
here presents the results of his investigations during three years 
residence in San Domingo, comprising facts relating to the topog- 
raphy and geology of 15,000 square miles, or about half the island. 
He states that the only fossiliferous rocks of the island, besides 
the Quaternary, are the Cretaceous, which are all more or less met- 
fhe metamorphic rocks referred to the Cretaceous are much up- 
turned and folded, the axes of the folds usually east and west, or 
parallel with the axis of the mountains. The rocks include, besides 
length, with some upturning, height in some cases 0 
or more, “making the Monte Christi Chain, where, until the 
oral origin. As it is not derived from the accumulation of 
Rhizopods, like true chalk, he has named the soft rock <A néiliite. 
The above are a few facts from this important memoir. 
3. Trachytie and Goleritie rocks in alternations in the Puebla 
the base to the summit, 1200 feet above, and vary in thickness from 
20 to 50 or more feet. The eruptions are stated by Dr. Blake to 
be probably early Miocene. The rocks of the beds are of both 
the doleritie and trachytic kinds. They include the varieties of 
