snakes; trisulcis

[Anthony Appleyard]

Virgil at least twice when mentioning snakes says that a snake "linguis micat ore trisulcis". "trisulcis" (dat/abl pl) means "having 3 grooves/furrows"; but snakes' tongues end in 2 points with only one cleft between them. But when watching snakes in zoos etc I often saw it flicking its tongue out twice so quickly that an observer may see each of the 2 points twice so that it looks as if the tongue ends in 4 points. And 4 points in a flat layer have 3 gaps between them. Thus "trisulcis".

[bedwere]

Maybe because he's counting as grooves/furrows the three empty spaces, like in the letter Y ? One on the top, one on the right, and one on the left.