Perry's Index to the Aesopica
721-725. Fables from Poggio and Abstemius
723. The Rustic seeking to Cross a River
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.