considered to mostly pre-date the spread of Christianity to the Picts, are essentially speculative. Many later Christian stones from Class II and Class III fall more easily into recognisable categories such as gravestones. The earlier symbol stones may have served as personal memorials or territorial markers, with symbols for individual names, clans, lineages or kindreds, although there are several other theories, and proposed explanations of the meanings of the symbols. Standard ideograms Class I and II stones contain symbols from a recognisable set of standard ideograms, many unique to Pictish art, which are known as the Pictish symbols. The exact number of distinct Pictish symbols is uncertain as there is some debate as to what constitutes a Pictish symbol, and whether some varied forms should be counted together or separately. The more inclusive estimates are in excess of sixty different symbols, but a more typical estimate is "around thirty", or "around forty" according to Historic Scotland. These include geometric symbols which have been assigned descriptive names by researchers such as "crescent" "V-rod" "double disc and Z-rod" "mirror and comb" "triple disc" and outline representations of animals such as adder salmon wolf stag eagle Pictish Beast (apparently mythical – perhaps intended as a sea monster) Some are representations of everyday objects, such as the "mirror and comb", which could have been used by high-status Picts. The symbols are almost always arranged in pairs or sets of pairs, often with the object type, such as the mirror and comb, below the others, and the animals are generally found only in combination with the abstract types. Hence some think they could represent names, lineage, or kinships, such as the clans of two parents, analogous to the Japanese mon. According to Anthony Jackson the symbol pairs represent matrilineal marriage alliances. Finds and associations A small number of Pictish stones have been found associated with burials, but most are not in their original locations. Some later stones may also have marked tribal or lineage territories. Some were re-used for other purposes, such as the two Congash Stones near Grantown-on-Spey, now placed as portal stones for an old graveyard. The shaft of an old cross is lying in the field. Another Pictish stone, the Dunachton Stone near Kincraig, was later used as a door lintel in a barn. This was discovered when the building was dismantled in 1870. The stone was re-erected in the field. Recently