Original: Chondrichthyes ( ) or cartilaginous fishes are jawed fish with paired fins , paired nares , scales , two-chambered hearts , and skeletons made of cartilage rather than bone .
Simplified: Chondrichthyes or cartilaginous fishes are jawed fis with paired fins , paires nostrils , scales , two-chambered hearts , and skeletons made of cartilage rather than bone .