THE CHAIN OF LIFE. 



though not published till some time afterward, and was fol- 

 lowed up by further collections in company with Sir Charles 

 Lyell in 1851, at which time also the earliest land-snail was 

 found, and in the following year the first millepede. Since 

 that time the progress of discovery has been astonishingly 

 rapid, and has extended over most of the principal coal-areas 

 on both sides of the Atlantic. 



Fig. 133. — Footprints of one of the oldest known Batrachians, probably a species ot 

 Dendrcrpeton From the Lower Carboniferous of Parrsboro', Nova Scotia. Upper 

 figure natural size. 



We may, for convenience, call these animals reptiles, but 

 they are regarded as belonging to that lower grade of reptilian 

 animals, the Amphibians or Batrachians, which includes the 

 modern frogs and newts and water-lizards.^ Still it would be 

 doing great injustice to the carboniferous reptiles not to say, 



^ MenoJ>oma, Menobranchus, etc. 



