The Eltdown Shards
The "disturbing and debatable Eltdown Shards" may have been the invention of William Lumley for his story "The Diary of Alonzo Typer" which Lovecraft revised. Possibly derived from the discovery of the "Piltdown Man."
[The Shadow Out of Time - H.P.L.]
[(PR)"The Diary of Alonzo Typer]