In all of the work referred to above, the separate pieces of marble or glass are carefully shaped to fit the patterns they are intended to form, and in this respect differ from the Byzantine and other wall mosaics, and from the earlier Roman mosaic pavements such as those which are familiar in the Pompeiian buildings. In the latter the shape and often the size of the pieces making up the pattern were of comparatively little importance, and the pieces were imbedded in a matrix which filled up the interstices and gave a background of neutral color. The marble pavements, made up of discs, squares, and other geometrical forms of colored marbles surrounded by bands or borders of a smaller scale, were similar in design to some of the mosaics shown in our plates. This work is known as Opus Alexandrinum and is familiar from the pavements of St. Mark's and the church of Santa Maria dei Miracoli in Venice. [Illustration: LXV. Ambo in the Capella Palatina, Palermo, Sicily.] The Capella Palatina was built and dedicated to St. Peter by King Roger the Second of Sicily. It must have been begun soon after Roger's coronation, and was finished in the year 1143. It is of the same period as the cloister of Monreale, which was described and illustrated in the March number of THE BROCHURE SERIES; and the work here shown distinctly recalls the mosaics upon the twisted columns in this cloister. The interior is famous as one of the most beautiful works of color decoration extant. Its general tone is bluish green with mosaic walls and floor and a wooden ceiling decorated in tempera with cufic inscriptions. It is scantily lighted with small windows, giving a rather sombre effect. The best mosaics are in the chancel and apses. The beautiful ambo is one of its most attractive features. The famous candelabrum of five tiers of figures, at the projecting angle, is of white marble. [Illustration: LXVI. Ambo in the Cathedral, Salerno, Italy.] [Illustration: LXVII. Pulpit in the Cathedral, Salerno, Italy.] Salerno and Ravello were both included under the Norman rule of the kingdom of Naples and Sicily in the eleventh century, and the work here shown all belongs to the Norman period. The Cathedral of Salerno was founded and dedicated to St. Matthew in 1084 by Robert Guiscard, who plundered the temples of Paestum of their marbles and sculptures to embellish it.