the European group, but also when the most recent equivalent 

 of the same group was formed, as now seen near the equator. 



It would far exceed our limits to enter into the general com- 

 parison which might be made, even to minute details, of the 

 living representatives and the depositions of the river Amazon, 

 and other parts within the south tropical zone, with the fossils 

 and deposits of the oolitic group ; and as it only forms but a 

 mere link in our chain of argument in support of the northward 

 movement of the surface, we must content ourselves with a ge- 

 neral glance. If this system of deposits was formed within the 

 south tropical zone, and should they be visible at the equator, 

 they must be very superficial, and in a very unconsolidated state 

 as compared with the European. The equivalent of the Euro- 

 pean oolitic group in equinoctial America, from the Amazon to 

 the Orinoco, and on the plains and table-lands of New Grenada, 

 is an immense mass of alternate beds of fine-grained quartzose 

 sandstone and conglomerates, containing Ammonites, Belem- 

 nites, and a variety of other marine shells, together with species 

 of fossil plants of the Cycadea?, Coniferae, &c; and on the super- 

 ficial, arenaceous and unconsolidated part of the same series 

 are found immense bones, considered to be the remains of the 

 Mastodon. These bones are very abundant in the province of 

 Nieva, amongst which are those of the alligator. 



In New Grenada this series of sandstone is stratified in layers 

 more or less horizontal ; a great number of the thinner and 

 upper seams are composed of decayed leaves and impressions of 

 plants the same as those now growing on the spot. On the 

 plains of Mariquita and Nieva are immense isolated terraces pre- 

 senting beautiful sections of 2000 feet high ; and also on the 

 plains of Bogota, resting on the coal formation of that district; 

 whilst on the west this formation rests immediately on the cry- 

 stalline schists of the central Cordillera. The elevation of this 

 part of South America from the level of the sea (which appears 

 to have been comparatively recent) was extremely uniform, and 

 about 3000 feet. According to the theory here brought forward, 

 it was not a mere vertical rise, but a diagonal movement from 

 the south. There are but few T beds of the oolitic group suffi- 

 ciently consolidated for building stones, and those that are so em- 

 ployed are much softer than the common freestone. Stems of soft 

 plants are commonly found, as black as jet, in the harder beds. 



