Diphycercal :: Diphycercal (a.) Having the tail fin divided into two equal parts by the notochord, or end of the vertebral column; protocercal. See Protocercal..
Heterocercal :: Heterocercal (a.) Having the vertebral column evidently continued into the upper lobe of the tail, which is usually longer than the lower one, as in sharks..
Homocercal :: Homocercal (a.) Having the tail nearly or quite symmetrical, the vertebral column terminating near its base; -- opposed to heterocercal..
Protocercal :: Protocercal (a.) Having a caudal fin extending around the end of the vertebral column, like that which is first formed in the embryo of fishes; diphycercal..