80 VERTEBRATA. PISCES. 



possessed by many sea-fishes: the Sun-fish, (Cephalus 

 Mold,} for example, is said to resemble an enormous 

 globe of iron at a white heat, when seen at night 

 many fathoms beneath the surface. 



Fishes are separated into two grand divisions 

 which may be termed Sub-classes. The Bony Fishes, 

 which are by far the most numerous, and which 

 more fully answer the description above given, have 

 a bony skeleton ; while the Cartilaginous Fishes, as 

 their name implies, have the skeleton formed of car- 

 tilage in place of bone, are destitute of ribs, and in 

 other respects seem subordinate to the former. 



