CLASSES OF VERTEBRATA, 195 
Finally, the paleontological records of creation are also 
of especial value in the case of these same Vertebrate 
animals; for their fossil remains belong for the most part 
to the bony skeleton, a system of organs which is of the 
utmost importance for understanding their general organiza- 
tion. It is true that here, as in all other cases, the fossil 
records are exceedingly imperfect and incomplete, but more 
important remains of extinct Vertebrate animals have been 
preserved in a fossil state, than of most other groups of 
animals; and single fragments frequently furnish the most 
important hints as to the relationship and the historical 
succession of the groups. 
The name of Vertebrate Animals (Vertebrata), as I have 
already said, originated with the great Lamarck, who 
towards the end of the last century comprised under this 
name, Linnzeus’ four higher classes of animals, viz. Mammals, 
Birds, Amphibious animals, and Fishes. Linnzeus’ two lower 
classes, Insects and Worms, Lamarck contrasted to the 
Vertebrata as Invertebrata, later also called Hvertebrata. 
The division of the Vertebrata into the four classes above 
named was retained also by Cuvier and his followers, and 
in consequence by many zoologists down to the present 
day. But in 1822 Blanville, the distinguished anatomist, 
found out by comparative anatomy—which Bar did almost 
at the same time from the ontogeny of Vertebrata—that 
Linnzeus’ class of Amphibious animals was an unnatural 
union of two very different classes. These two classes were 
separated as early as 1820, by Merrin, as two main groups 
of Amphibious animals, under the names of Pholidota and 
Batrachia. The Batrachia, which are at present (in a 
restricted sense) called Amphibious animals, comprise Frogs, 
