'Protocercal' definitions:

Definition of 'Protocercal'

From: GCIDE

Protocercal \Pro`to*cer"cal\, a. [Proto- + Gr. ? the tail.] (Zool.) Having a caudal fin extending around the end of the vertebral column, like that which is first formed in the embryo of fishes; diphycercal. [1913 Webster]