The churches are usually small, and have an apsidal east end. The openings are rude, with round-headed arches and small single or two-light windows, and the outer walls are generally marked by flat pilasters of very slight projection. Towers are common, and the openings in them are often divided into two or more lights by rude columns. The plan of these churches was founded on the basilica type, but they do not exhibit the same internal arrangement; and it is very noteworthy that many of them show marks of having been vaulted, or at least partly vaulted; and not covered, as the basilicas usually were, by timber roofs. Even a country so remote as Great Britain possessed in the 10th century many buildings of Primitive Romanesque character; and in such Saxon churches as those of Worth, Brixworth, Dover, or Bradford, and such towers as those of Earl's Barton (Fig. 166), Trinity Church Colchester, Barnack, or Sompting, we have specimens of the style remaining to the present day. By degrees, as buildings of greater extent and more ornament were erected, the local varieties to which reference has been made began to develop themselves. In Lombardy and North Italy, for example, a Lombard Romanesque style can be recognised distinctly; here a series of churches were built, many of them vaulted, but not many of the largest size. Most of them were on substantially the same plan as the basilicas, though a considerable number of circular or polygonal churches were also built. Sant' Ambrogio at Milan, and some of the churches at Brescia, Pavia, and Lucca, may be cited as well-known examples of early date, and a little later the cathedrals of Parma, Modena, and Piacenza (Fig. 167), and San Zenone at Verona. These churches are all distinguished by the free use of small ornamental arches and narrow pilaster-strips externally, and the employment of piers with half-shafts attached to them, rather than columns, in the arcades; they have fine bell-towers; circular windows often occupy the gables, and very frequently the walls have been built of, or ornamented with, coloured materials. The sculpture--grotesque, vigorous, and full of rich variety--which distinguishes many of these buildings, and which is to be found specially enriching the doorways, is of great interest, and began early to develop a character that is quite distinctive. [Illustration: FIG. 167.--CATHEDRAL AT PIACENZA.]