The Ptetholite language is a fictional language system which appeared in Brian Lumley's short story The Caller of the Black.
The Ptetholite language and its subsequent script are one of the few existing remnants left by the Ptetholite People: a prehuman race which antedated the Hyperboreans. Though little is known about the language itself, we do know that the script was sometimes used for writing curses and incantations.
Few traces of the Ptetholites or their language remain. Fragmentary examples of the script may remain in such Hyperborean records as the Liber Ivonis or the Testament of Carnamagos. Earlier translations of the Cthäat Aquadingen contain a version of the Sixth Sathlattae written in Ptetholite script.
The best preserved examples of the Ptetholite script can be found upon the Broken Columns of Geph situated on the cost of Liberia. Inscribed upon the columns is a long narrative recording the Ptetholite peoples magic and its use in there wars. However the complete message is undecipherable since a number of the columns have been defaced and some of their contents erased by the Mi-Go.
An item known as the Phitmar Stone is said to bear three inscriptions; two in Old Kingdom Egyptian dialects and one of a selection of letters copied from the above mentioned columns. Whether the Egyptian sections are actual translations of the columns transcripts or merely descriptions is unknown.