This is the listening part, the twisting bits of the inner ear. It really does look like a mollusk, doesn’t it? (“Cochlea” literally means “snail” in Greek.)
It was drawn (or engraved) by Henry Vandyke Carter in the mid-1800s, though published in 1910. Before illustrating Henry Gray’s Anatomy, descriptive and surgical, Carter had previously “worked for John Queckett, the first expert of microscopy, and Richard Owen, one of the best anatomists of the Victorian era” as part of the Royal College of Surgeons. After the several years spent with Gray, illustrating his textbook among other things, Carter went off to India to actually practice medicine. The first edition of Gray’s Anatomy was published in 1858, and gradually became a world-renowned classic of medical information. Carter went on to lead a life probably more interesting than he’d counted on, but did manage to advance the cause of medicine before returning home to England and, less than 10 years later, dying of consumption.
His illustrations remain to this day a gold standard for scientific illustration, however.