70 



ACADEMIC BOTANY. 



Series II. — Vertebrates, with spinal column ; producing eggs. Ke- 

 production by fertilization. Five classes : 



1. Fishes (Herring, Salmpn, Cod, Shark). ' 



2. Amphibians (Salamander, Mud-Eel, 

 Frog). 



3. Reptiles (Turtle, Snake, Lizard, Alli- 

 gator). 



4. Birds (Goose, Ostrich, Parrot). 



Oviparous ; young de- 

 veloped in the egg after 

 it separates from the 

 mother. 



5. Mammals (Opossum, Sloth, "Whale, 

 Oat, Kat, Bat, Mole, Monkey, Man). 



Viviparous ; young 

 developed in the egg in 

 the mother's body, and 

 suckled by the mother 

 after birth. 



187. Lifeless Time. Though the layers of later periods are placed in 

 regular succession, the Lifeless, or Azoic rocks (sometimes called 

 Archcean)i have been thrust up at various times by internal commo- 

 tions, and are seen at the surface in Norway, Sweden, Bohemia, and 

 Scotland. They are remarkably exhibited in North America, especially 

 in Canada (called the Laurentian rooks, from the river St. Lawrence), 

 and extending along the Allegheny and Blue Ridge ranges to Ala- 

 bama ; also in the Kocky Mountains. America is indeed the Old 

 World rather than the New. Some of her living quadrupeds (Opos- 

 sum, Sloth) and one of her races of men (Esquimaux) are found 

 elsewhere only in fossils. 

 138. Ancient Time has four periods : 



1. Silurian (L. Silures, the Welsh), because these rocks abound in 

 Wales. 



2 Devonian, from Devon, England ; sometimes called Old Eed 

 Sandstone. 



3. Carboniferous, from the abundance of its coal-measures. 



4. Permian, from Perm, in Russia. 



-- B 



Fia. 83. — A, Pidteorliftrda minor, seaweed, fossil, Scotland. B, Oldhamia anliqua, 

 animal, fossil, Ireland. 



129. In the Lower Silurian (see Table) are the first authentic fossils. 

 The plants are Thallogens ; one of them is a Seavjeed (Fig. 83, A), 

 resembling the I)ead-Man's-Rope of our own time (Book-cover, front). 

 Another is an Invertebrate animal, also marine, like our Sea-Fir (Fig. 

 88, B). In the Upper Silurian land plants appear; AcRoaaifS, — Ferns 



