资料来源 : Webster's Revised Unabridged Dictionary (1913)

Protocercal \Pro`to*cer"cal\, a. [Proto- + Gr. ? the tail.]
   (Zo["o]l.)
   Having a caudal fin extending around the end of the vertebral
   column, like that which is first formed in the embryo of
   fishes; diphycercal.