194 WHAT IS LIFE? 



bore naked seeds, as are found in the pines of the present 

 day. Certain varieties of plant life peculiar to the 

 Permian system have died out. The horse-tail plants 

 are still abundant. Ferns and cycads are the domi- 

 nant plants. 



Shell-fish are abundantly and admirably preserved 

 in these formations, but the lower forms decrease in 

 importance. Oysters are now in abundance, and the 

 modern bivalves and univalves largely predominate 

 over the brachiopods. Corals of modern type are 

 found in these strata. Ammonites, extinct relations 

 of our Nautilus, lived in variety. The ancient 

 trilobites are replaced by long ten-footed lobsters and 

 prawns, the representatives of our modern lobsters. 

 Terrestrial insects flourished, including dragon-flies 

 and may-flies. Also there were cockroaches and 

 grasshoppers, and numerous beetles. Indications of 

 butterfly life appear. 



The special types of ganoid fishes that were charac- 

 teristic of the Primary rocks are now dying out. Rays 

 and sharks, however, still form the most prominent 

 fishes. But the most remarkable feature of these strata 

 is the abundant remains of reptiles. True turtles were 

 created when these layers of rock were deposited. One 

 of the most remarkable sea-lizards was a creature with 

 a fish-like body, two pairs of strong swimming paddles, 

 probably a vertical tail-fin, and a head jointed to 

 the body without any distinct neck, but furnished 

 with two large eyes, having a ring of bony plates 

 round the eyeball, and with teeth that had no 

 distinct sockets. Some of these creatures measured 

 twenty- four feet in length. Another monster had 

 a long neck, large-sized paddles, and smaller head 



