They are divided into two subclasses : PERSON@1 -LRB- sharks , rays and skates -RRB- and PERSON@2 -LRB- chimaera , sometimes called ghost sharks , which are sometimes separated into their own class -RRB- .

They are divided into two subclasses : PERSON@1 -LRB- sharks , rays and skates -RRB- and PERSON@2 -LRB- chimaera , sometimes called ghost sharks -RRB- .
