MS M.383 has no quire structure. Its bifolia were cut into single leaves during a previous binding.
Prior to the mid-20th century rebinding by Marguerite Duprez Lahey, the Morgan Library published this collation based on examination of the spine of the 19th century binding. This is unlikely to have been the case since the Soranzo foliation found in the bottom margin (in parenthesis here) shows that by the 18th century, 14-16 (but not 17) were bound between 1 and 2, so those six had already been cut into single leaves and the others presumably had as well.
