THE CARBONIFEROUS PERIODS 



4 8 S 



sence of all sucking insects, such as bees, wasps, and butterflies, whose 

 food consists of the nectar of flowers procured by a sucking apparatus, 

 and in fact of all insects which depend upon flowers for food is not 

 surprising, since no flowering plants were in existence at this time. 



The active dragon fly rather than the sluggish amphibian (p. 489) 

 might seem " a far superior type of being, a far more promising can- 

 didate for the position of ancestor of the intelligent life which was to 

 appear in the dim future/' " But the insect had fulfilled the mechan- 

 ical possibilities of which his structural organization was capable." 

 (Matthew.) 



Vertebrates of the Carboniferous 



Fishes. — During the Mississippian sharks existed in an abundance 

 which has not been equaled before or since, as is shown by the large 

 number of species, of which nearly 300 have been de- 

 scribed. Before the close of the Carboniferous, how- 

 ever, the number had become very small, only about 

 20 species being known in the Permian. As in the 

 Devonian, the sharks are known from their fin spines 

 and teeth (Fig. 460), the latter being of the crushing 

 type. The sharks were, for the most part, small, 

 being seldom more than five feet long, while none 

 attained the size of their modern relatives. 



Only sharks and typical ganoids (Actinopteri) were 

 important, the armored lungnsh and fringe-finned 

 ganoids having reached their climax in the Devonian. 



Amphibians. — Next to the appearance of the fishes 

 the most important event in the history of vertebrates 

 was the rise of amphibians, of which the salamanders, 

 newts, and frogs are modern representatives, since the A back spine 

 ancestors of reptiles, of mammals, and even of man tooth, and scale 

 himself are to be found among them. Amphibians °f a Mississip- 

 resemble reptiles, but differ from them in the fact that pian s 

 in the earlier period of life they breathe in water by means of gills, 1 

 like fishes ; and it is only in the later period of life that they breathe 

 air by means of lungs, like reptiles. The most important difference 

 between fishes and amphibians is in the organs of locomotion, fishes 

 having fins and amphibians legs, in the adult stage. 



1 Some amphibians never lose their gills. 



