Professor Petrie acquired the plaque at Memphis. He considers that it dates from a period round about 3000 B.C., and points out that if the broken lines be completed there would appear to be five false turns to be avoided before reaching the centre. [Illustration: FIG. 19.--Early Egyptian Plaque or Amulet. (Prof. Petrie's Collection, University College, London.)] In discussing the designs on these seals and plaques, Sir A. Evans alludes to a possible connection with two of the hieroglyphs of the period, which are of the nature of simple square meanders of a kind extensively employed in ancient ornament. One of them (_mer_) is the sign used for indicating irrigated land. The other (_aha_) is a simplified form of a more elaborate sign representing the plan of a palace court, a figure to which one of the Minoan signs bears a close resemblance. The Knossian coins shown in Figs. 20 to 31 are from the British Museum collection and are reproduced by the courtesy of the Keeper of the Coins and Medals Department, who supplied the writer with plaster casts for the purpose. They date, of course, from times greatly posterior to those of the Minoan civilisation, from times when the culture of Greece had long replaced that of the Mycenaeans, or whatever similar race it was that succeeded the Minoans (see Appendix IV, i.). Figs. 20, 21, and 22 show silver coins dating from about 500 to 430 B.C. They portray on one side the Minotaur and on the other a symmetrical meander pattern which, it needs very little imagination to see, has reference to the labyrinth in which the monster was alleged to dwell. Fig. 23 shows a silver coin of a rather later date, representing on its obverse a female head which is thought to be that of Demeter or Persephone, and on the reverse a meander-labyrinth containing a star at its centre. Fig. 24 shows a similar obverse, but on the reverse we see a bull's head surrounded by a simple meander frame. Fig. 25, the obverse of which is likewise adorned with a female head, gives on the reverse the design of a square labyrinth of the conventional type that thereafter predominates. Fig. 26 shows a bronze coin having on one side the head of Apollo and on the other a labyrinth with a star. The four coins last described date from a period between 430 and 350 B.C. The next (Fig. 27) is rather later in date and shows on its obverse the head of Hera and on the reverse a square labyrinth together with an arrow-head and thunderbolts and the Greek characters ΚΝΩΣΙΩΝ [Greek: KNÔSIÔN]. [Illustration: Figs. 20 to 25. Coins of Knossos. (British Museum)] The bronze coin of about 220 B.C., shown in Fig. 28, bears on its obverse the figure of Europa seated on a bull, with two dolphins below, and on the reverse a square labyrinth, the Knossian superscription being again evident. The remaining three figures represent silver coins of the two succeeding centuries, but not later than 67 B.C.