The horn of the hoof wall that is produced by the coronary dermis. The stratum medium makes up most of the wall substance.

It consists of many elongated cylinders of horn (horn tubules) lying parallel to each other and running continously from the coronary band to the bearing edge. The horn tubules are grown from the epidermis of the cornary papillae; between the tubules, the strong intertubular horn forms a matrix in which the tubules are embedded. This type of horn grows from the coronary epidermis between the papillae.The horn varies slightly in structure and pigmentation from the outer-most layers (high tubular density, usually pigmented) to the inner-most layers (low tubular density, un-pigmented).