During the Middle Ages portable altars (_altares portátiles_) were widely used in Spain, and some were made of ivory. It was the custom to open them at the time of prayer, and as a rule they rested upon _reclinatorios_ or hung upon the wall. The _imagen abriente_ or "opening image" was also popular in Spain throughout the twelfth and thirteenth centuries. As the name implies, these images opened in the manner of a triptych, and were very often used as reliquaries. Specimens are preserved in many parts of Europe, but only one or two exist in Spain and Portugal. That which belongs to the nuns of Allariz dates from the end of the thirteenth century, and was a present from Queen Violante. It is described fantastically by Morales, and accurately by Villa-amil, but the quaintest account is by the chronicler Jacobo de Castro. It measures, Castro tells us, "about half-a-yard in length and is one of the fairest ever seen, since it opens downward from the neck, discovering, on plates of half-relief, the principal mysteries of Christ and of Our Lady. The devotion towards it of the people in this neighbourhood exceeds description, and God has wrought a quantity of miracles through the intercession thereof." A fourteenth-century triptych carved in bone with scenes from Scripture is in the National Museum. It proceeds from Aragon, and is said to have belonged to Jayme the Conqueror. The Escorial possesses a handsome ivory diptych (Plate xlvi.) which is either Spanish or Italian--probably the former. It measures exactly a foot in height by nine inches across both leaves, and is deeply carved with passages from the life of Christ. The style is late Romanic merging into Gothic, and points to the second half of the thirteenth century. [Illustration: XLVI IVORY DIPTYCH (_13th Century. El Escorial_)] POTTERY ANCIENT Quantities of ancient common pottery have been, and are continually being found in many parts of Spain. Prehistoric cups, shaped with the fingers and dried and hardened by the sun, are preserved in the Museum of History at Barcelona. They were discovered at Argar. Similar objects have been extracted from the caves of Segóbriga, Lóbrega in Old Castile, and El Tesoro in the province of Málaga. Those which were found at Segóbriga are divided by Capelle into six groups, one of which includes a vessel resembling the ordinary Spanish pitcher of to-day.