Sphincter colli profundus

The sphincter colli profundus is usually well developed; but seams absent in Pigs, Bulls, and small Ruminants. Its beams go from one side of the neck to the other and end dorsally and ventrally on the median raphe. In numerous species (Equidae, Carnivorous) its more caudal beams are directly attached to the sternal manubrium.

It also continues on the face and dissociates itself. We generally agree that the cutaneous muscles of the face are isolated and diferentiated parts of it.