The Apex of the nose (Apex nasi) is framed by the nostrils (Nares). It ends the chamfer and projects over the upper lip, with which it forms the rostrum. The disposition and the aspect of the rostrum , aswell as the nostrils vary much according to the specie.
In Horses, the rostrum forms a strong and mobile appendix, finely hairy. Each nostril holds in its dorsolateral wall a deep cutaneous dead end that invaginates itself in its lateral commissure: the nasal diverticulum or false nostril (Diverticulum nasi).
In Bulls, the rostrum constitutes the muzzle (Planum nasolabiale), a wide hairless and wet surface.
In Pigs, it is the snout (Planum rostrale) and in Carnivorous, the truffle (Planum nasale), hairless and generally pigmented.