98 



ISLAND LIFE 



PART I 



New Jersey, Alabama, Kansas, the sources of the Missouri, 

 the Rocky Mountains from New Mexico to the Arctic 

 Ocean, Alaska, California, and in Greenland and Spitz- 

 bergen; while birds and land reptiles are found in the 

 Cretaceous deposits of Colorado and other districts near the 

 centre of the Continent. Fresh-water deposits of this age 

 are also found on the coast of Brazil. In the lower part of 

 this formation we have the fresh-water Wealden deposits 

 of England, extending into France, Hanover, and West- 

 phalia. In the older Oolite or Jurassic formation we have 

 abundant proofs of continental conditions in the fresh-water 

 and " dirt "-beds of the Purbecks in the south of England, 

 with plants, insects and mammals; the Bavarian litho- 

 graphic stone, with fossil birds and insects ; the earlier 

 " forest marble " of Wiltshire, with ripple-marks, wood, and 

 broken shells, indicative of an extensive beach ; the Stones- 

 field slate, with plants, insects, and marsupials ; and the 

 Oolitic coal of Yorkshire and Sutherlandshire. Beds of the 

 same age occur in the Rocky Mountains of North America, 

 containing abundance of Dinosaurians and other reptiles, 

 among which is the Atlantosaurus, the largest land-animal 

 yet known to have existed on the earth. Professor O. C. 

 Marsh describes it as having been between fifty and sixty 

 feet long, and when standing erect at least thirty feet 

 high ! ^ Such monsters could hardly have been developed 

 except in an extensive land area. A small mammal, 

 Dryolestes, has been discovered in the same deposits. A 

 rich Jurassic flora has also been found in East Siberia and 

 the Amur valley. The older Triassic deposits are very 

 extensively developed in America, and both in the Con- 

 necticut valley and the Rocky Mountains show tracks or 

 remains of land reptiles, amphibians and mammalia, while 

 coalfields of the same age in Virginia and Carolina produce 

 abundance of plants. Here too are found the ancient 

 mammal, Microlestes, of Wurtemberg, with the ferns, 

 conifers, and Labyrinthodonts of the Bunter Sandstone in 

 Germany ; while the beds of rock-salt in this formation, 



^ Introduction and Succession of Vertebrate Life in America, by Professor 

 0. C. Marsh. Reprinted from the Popular Science Monthly, March, April, 

 1878. 



