From the list in the back of the sketchbook: Page 1 Copy of a drawing of the school of Mantegna entitled 'The Calumny of Apelle' . British Museum (see p. 173 in Mantegna by G. Fiocco).
"The Calumny of Apelles" a drawing by mategna after a lost painting by the Greek Artist Apelles now in the Brtish Museum Acc no 1860,0616.85