Perry's Index to the Aesopica
Perry reserves 431 for a long story narrated by Callimachus about the
language of humans and animals. Various fragments of this work by Callimachus
continue to be discovered.
You can find a compilation of Perry's index to the Aesopica in the gigantic appendix to his
edition of Babrius and Phaedrus for the Loeb Classical Library
(Harvard University Press: Cambridge, 1965). This book is an absolute must for anyone interested
in the Aesopic fable tradition. Invaluable.