anfc Kite. 9 



rocks of the Devonian period. It is called 

 Silurian, from the name of a kind of fish, fos- 

 sils of which are found in the rocks of this 

 age, which are distinguished for the absence of 

 land-plant fossils and vertebrate animals. 



In i;he Silurian strata are found limestones, 

 slate, 'flagstones, shales, etc. On top of the Si- 

 lurian begins the " Devonian " age, in which 

 is found the old red sandstone, as well as lime- 

 stone and slate; and here begin to be found 

 the fossils of land-plants. On top of the De- 

 vonian lies the " Carboniferous " series, which 

 complete the series of the primary period. In 

 the lower part of this stratum is found car- 

 boniferous limestone, which is overlaid by a 

 kind of stone called millstone grit, and on top 

 of this lie the true carboniferous strata or 

 coal-bearing measures. In the coal strata are 

 found the first reptile fossils. 



On top of the coal measures begins the Sec- 

 ondary period, or " Mesozoic " (middle life). 

 This period is distinguished for the great de- 

 velopment of reptiles, and is called the " age 

 of reptiles." In this age occur the first traces 

 of mammals, and birds, and fishes with bony 

 skeletons. Among plants we find here the 

 first evidence of palms. The formation is 

 chiefly chalk, sandstones, clays, limestone, etc. 

 We now come to the last or " Tertiary " period, 

 which brings us to the top earth. This is 

 chiefly formed of sedimentary rocks those 



