Animals Before Ma 



n 



tant; while the third comprises the sharks, 

 chimeras, sturgeons, and the hosts of true or 

 bony fishes which form the vast majority of 

 the class. The lampreys, which deserve more 

 than passing notice, because they mil often be 

 referred to, have no jaws or limbs, and a soft 

 backbone without even a hint of divisions into 

 joints or vertebrae. Still, low as they are in the 

 scale of vertebrate life, they date back almost 

 to its commencement ; though while they may 

 be respected for their ancient lineage, they may 

 also serve as a warning that fortunately the 

 importance of a family does not depend upon 

 the length of its pedigree. 



At the very lowest end of the back-boned 

 animals, occupying a somewhat intermediate 

 place between what may be termed true verte- 

 brates and true invertebrates, are the curious 

 sea squirts, forming the class Tunicata, and 

 the equally strange, but even less known ani- 

 mals of the class Enteropneusta ; so little 

 known, indeed, are they as to have no common 

 name. These are the animals referred to as 

 vertebrates in disguise, or degenerate verte- 



38 



