Placing of rocks

After the word "menhir" was misspelled in the championship round of the National Spelling Bee, I made a note to sort out the difference between a monolith, a menhir, and a cist. In the process of doing that, I found plenty of similar words. Killing two birds with one stone - or as a former boss used to say, in the interest of political correctness, releasing two birds with one gesture - I have sorted out the synonyms with both definitions and black and white photographs:
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dolmen n. Two large upright stones capped by a horizontal stone, usually regarded as a tomb; a cromlech. dolmenic, adj.
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menhir n. A large stone set upright in ancient times - either alone or with others - as a monument or memorial; a standing megalith.
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megalith n. A very large stone, esp. as used in prehistoric architecture; a menhir. megalithic, adj.
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cist n. A prehistoric grave lined with stones and often having a lid of stone; a dolmen. cisted, cistic, adj.
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cairn n. A heap of stones set up as a monument or burial marker. cairned, cairny, adj.
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cromlech n. A prehistoric monument of rough stones supported in horizontal position by others; a dolmen.
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barrow n. A large mound of earth or stones placed over a burial site; a tumulus.
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tumulus n. An ancient grave mound; a cairn or barrow.