46 THE LESSON OF EVOLUTION 



This flora spread over North America, Europe, 

 South Africa, India, and Australia; but no trace of 

 it has as yet been found in New Zealand, nor in 

 South America. 



At the close of the Carboniferous period the large 

 Lycopodiacese and Cordaites died out ; and only a 

 few species of Calamites lingered on into the Per- 

 mian, the flora of which was composed of ferns, 

 cycads, and coniferae, especially the last. 



In the Devonian period Neuropterous insects 

 (May-flies) came on the scene ; and in the Carboni- 

 ferous forests were many others belonging to the 

 Orthoptera (Cockroaches and Locusts) and Hemip- 

 tera. But there were no beetles, moths, flies, ants, 

 or bees; while, in addition to millipedes and scor- 

 pions, we now find spiders and land-shells. 



The first land-vertebrates were Amphibians, or 

 Batrachians ; which change their mode of respira- 

 tion from aquatic to aerial during their life, and are 

 easily distinguished from fishes by their nostrils. 

 They were represented in the lower Carboniferous 

 period by the Labyrinthodontia, so named from the 

 labyrinth-like appearance of a transverse section of 

 a tooth, owing to its complicated folded structure, 

 which is something like that of the early Crossop- 

 terygii. The Labyrinth-odonts died out at the end 

 of the Triassic period, and were most abundant in 

 the Permian, when they spread as far as Tasmania, 

 and perhaps to New Zealand. Many kinds have 

 been described, ranging in size from a few inches to 

 seven or eight feet in length. In shape, too, they 

 were very varied, some representing lizards, others 



