50 ROZELLE PURNELL HANDY 



with streams and rivers, it is surprising that so little sedi- 

 ment found its way into the coal beds. This puzzled the 

 geologists until Sir Charles Lyell explained it. He noticed 

 on one of his visits to America that the Mississippi river is 

 highly charged with sediment where it flows through the 

 cypress swamps, but that when it passes through the close 

 undergrowth the sediment becomes precipitated, and the 

 water filters through in an almost pure state. This accounts 

 for the presence of thin partings of sandstone and shale 

 which frequently occur in coal deposits. 



The seas of the carboniferous age abounded in animal 

 life, as is evidenced by the organic remains found in the 

 alternating strata. Fishes and sharks of mammoth size 

 inhabited the warm waters of the deep oceans and crinoids 

 and corals, an infinite variety of articulates, crustaceans, 

 and trilobites infested the more shallow salt water areas. 

 The forest jungles teemed Vvith insect life — spiders, scor- 

 pions, centipides, mayflies, cockroaches, and crickets. There 

 were also numerous varieties of land snails. In this age 

 reptiles make their appearance for the first time. Their 

 footprints as impressed on the carbonaceous beds of Pennsyl- 

 vania indicate that they were large animals and that they 

 had tails, tail marks being discernible on the m^ud flats over 

 which the reptiles marched. In the Nova Scotia coal meas- 

 ures fossils have been found of the sea saurian, a species 

 of reptile that had paddles like a whale. Before the last 

 period of the carboniferous age had passed away, there were 

 still higher reptiles — those that lived on the land, but so 

 far there is no indication that birds or mammals existed as 

 early as this period. To account for the stupendous move- 

 ments which must have happened in order to bring about 

 the successive growths of forests one above the other, the 

 geologist attributes them to the action of heat and to vol- 

 canic activity, as is evidenced by the frequent occurrence of 

 what is known as faults. 



A glance at any modem geological map evidences the 

 bountiful manner in which nature has laid out beds of coal 

 upon the ancient surfaces of our earth, America alone con- 



