Sentence:  But we end with those famous Artists leauing them to their graues, and their works to the admiration of all posterity, and speake of Statuary or Caruing, which thus farre differeth from painting; this doth expresse hir image in the plaine or smooth superficies <WSD>imaginarily</WSD>; the other in the hollow and vneuen superficies, really. 
Meaning of the word marked with <WSD> tags:  In an imaginary way, in the imagination.