"Additional manuscripts" is the title given to those manuscripts in the British Library that are not in one of the various closed collections (Sloane, Harley, Royal etc.).
The early biblical manuscripts are titled by their numbers in the Gregory-Aland numbering ("Lectionary 123", "Uncial 345" etc.), not their BL numbers.
The following 144 pages are in this category, out of 144 total. This list may not reflect recent changes.