Corpses of Siamese twins, Everard Crijnsz. van der Maes, 1630, The Hague Historical Museum. This image was kindly sent in by Morbid Anatomy reader Pipi Lotta in the Netherlands, who explains:
This painting was painted by order of the Court of Holland and donated to the Theatrum Anatomicum. In 1628 the States of Holland had payed Gerrit Claesse from Woerden 50 guilders for the bodies of his Siamese daughters. The Government wanted to do autopsy in the examination hall of the Theatrum Anatomicum and do so research on conjoined twins.To read about this painting in the original dutch, click here. To find out more about the exhibition in which it was shown, click here.
Apparently it was such a special event that the painter Van der Maes was commissioned to make a painting of it. He got paid for 36 guilders.