The shell and rope patterns are even worse and more feeble; they are easily seen to be executed by different hands.

The simple bosses of the base under "Dawn and Evening" are still unfinished: that would go to prove that Michael Angelo had designed them and seen them cut as far as they go--not necessarily that he had seen them in position--and that the academicians, when they did their best to complete the chapel, rightly decided to leave them as they were.
The base under Day and Night has no bosses; they had not been begun as in the former case; we may presume the academicians thought it best to have them flat.

These simple bases are the most effective portions of the architectural scheme of the monument, in character with the allegorical figures, reminding us of the plinths or seats provided for the Athletes and the Prophets of the Sistine.

Perhaps they were the only portions, except the figures and the panelling of the walls, seen by Michael Angelo himself.

The supports and lid of the sarcophagi, and the sarcophagus of Giuliano, are of different marble to the actual receptacle of the body of Lorenzo, that is under Dawn and Evening.