In this, the piers have engaged shafts with capitals having plain mouldings or enriched with finely carved foliage of the oak, maple, or mallow. The pier arches have mouldings of three orders, also enriched, usually with the characteristic ball flower, or foliage similar to that upon the capitals. The TRIFORIUM consists of double arches, with subordinate cusped arches, adorned with Geometric tracery. The inner arcading of the Clearstory is absent, the one large window being divided by mullions and geometrical tracery, or by equilateral triangles enriched with circular and bar tracery (fig. 3, plate 14). Above the pier capitals an enriched corbel is usually placed from which springs the vaulting shafts, terminating with a richly carved capital under the Clearstory string. The aisle arcading, as a rule, is very beautiful, having geometric tracery and finely proportioned mouldings, the aisle windows with mullions and bold geometric tracery. The circular rose windows of the transepts are typical of this period. PERPENDICULAR AND TUDOR. The PIERS of this style are lofty and enriched with shallow mouldings carried round the pier arch, where capitals are introduced, they frequently resemble a band round the pier at the springing of the arch, or occasionally they are octagonal in form, and decorated with an angular treatment of the vine. In some instances, the upper part of the plain octagonal capital is relieved with an embattlement. The latter is also frequently used as a cresting for the elaborate perpendicular screens, or for relieving the clearstory strings.