William Camden's illustration of Stonehenge as it appears in the 1610 edition of Britain, or, A chorographicall description of the most flourishing kingdomes, England, Scotland, and Ireland, and the ilands adioyning, out of the depth of antiqvitie: beavtified with mappes of the severall shires of England/written first in Latine by William Camden; translated newly into English by Philémon Holland... :-) refers to -

Stones called Corsestones, Weighing 12 tunne, carrying in height 24. foote; in bredth, 7-foote; in compasse, 16.

What's a 'Corsestone'? Anyone any idea of the etymology here?