herring-bone work
Masonry in which the stones are laid aslant instead of being bedded flat; it is very commonly found in rough walling, and occassionally, in the Norman style, in ashlar work. Square tiles are sometimes arranged in the same fashion, especially in the backs of fireplaces, e.g. at Corfe Castle. This masonry is not to be relied upon as evidence of the date of a building, though it is frequently of the eleventh century… (Parker, 1896)