Manuscript fragment with historiated initial ("S")

Manuscript fragment on parchment, with text on one side. The main text (in Latin) has decorated capitals in red and blue penwork, and a small historiated initial ("S"), with details in gold. The colors have been washed out, but there are traces of green, blue and red. The historiated initial shows a bedridden man and two (female?) attendants. There is also a hybrid creature that springs from the letter, holding an arch on a stretched arm, with claws as feet and a long tail that becomes a branch of vine leaves. The main text is surrounded by commentary and there are also marginal annotations. The script looks like 13th-15th century small textura bookhand. The fragment was used in a binding. 35 x 20 cm