1, p. 166, l. 3057 and the commentary in Vol. Meleager LXI in Hellenistic Epigrams , Vol. Amakhaniai sun adelpheai'. For the passive, h. Merc. Generally, see LfgrE s.v. amekhanos, cols.
Most lexicons define 'herpeton' as an animal or beast that goes about on all fours.
Where the qualification 'on all fours' comes from, I do not know. The earliest instances of the word are, apart from this fragment, Odyssey 4.418, Alcman fr. 13.1 W., and Heraclitus fr. A Commentary on Homer's Odyssey Vol. 11 D. think 'herpeta' designates 'l'ensemble des especes qui vivent a la surface de la terre . . .