The few cylinder seals of the Hyksos period that are known are of medium size (fig. 23), with narrow perforation, and are somewhat like those of the earlier half of the Twelfth Dynasty. The specimens of the Eighteenth and later Dynasties vary in size considerably, but they always have a narrow perforation (fig. 24). [Illustration: Fig. 22. A CYLINDER SEAL OF AMENEMHAT III.] [Illustration: Fig. 23. A CYLINDER SEAL OF KHŶAN. (Cairo.)] [Illustration: Fig. 24. A CYLINDER SEAL OF SEN-MUT.] [Sidenote: Material.] Although comparatively few specimens have been found in wood, it is clear from many clay impressions[83] that cylinder seals were generally made of this material. One example of wood was found at Abydos[84] having the inscription written upon it in ink, showing that the design was sketched out on the cylinder by a scribe before it was cut by the engraver. Next to wood, the commonest material in early times was black steatite; but a few specimens have been found of hæmatite, green jasper, and ivory. Copper and bronze examples appear during the Fifth and Sixth Dynasties, and glazed pottery specimens appear a little later. White or grey steatite, coated with blue or green glaze, was the favourite material of the Twelfth Dynasty kings and officials, and this material was in vogue till the Nineteenth Dynasty. At the beginning of the Eighteenth Dynasty carnelian cylinder seals make their appearance, and the latest specimen known is of this hard stone. [Sidenote: The subjects engraved upon Egyptian cylinder seals.] The subjects engraved upon Egyptian cylinder seals may be grouped into three well defined divisions. Firstly, there is a small class the engraving on which depicts figures of men and animals, sometimes very beautifully executed. Secondly, a much larger class, represented by several hundred specimens, which bear true hieroglyphic inscriptions. Thirdly, a very small class with scroll patterns or other ornamental devices. [Sidenote: I. Figures of men and animals.] The specimens of the first class require to be studied in some detail, for they contain elements which are of great importance to the comparative archaeologist. A typical example is given in fig. 25, and a second will be found in Pl. III, fig. 1. One of the most distinctive features of these seals is the double-forequartered animal, a feature which occurs again on the button-shaped seals[85] of the period intervening between the Sixth and the Twelfth Dynasties. This does not appear to be an Upper Egyptian _motif_, but one common to the Delta and to an early civilization of Western Asia. [Illustration: Fig. 25. IMPRESSION FROM A CYLINDER-SEAL IN THE BERLIN MUSEUM.]