A study of a naked man seated to the right with his legs apart, his right arm raised to head height, and his left hand at his groin. His lowered head has a satyr-like character. RCIN 903830 and 903831 did not originally belong to the Castiglione volumes, but had been inserted loose into them, presumably on the basis of the inscription at the bottom of RCIN 903831. The pose of the figure is almost identical in both cases. No academies by Castiglione are known, so that there is no means of checking the traditional attribution.The style is very close to that of Andrea Sacchi.