From
Voyage de la corvette l'Astrolabe Zoology [Atlas, Mollusques] (1833) by Dumont d'Urville et al.:
Illustrations of a sea hare (top) and a sea snail known colloquially as an “episcopal miter” (bottom). While both names are a bit questionable, I do think the latter looks more like a bishop’s hat (miter) than the former looks like a hare.
Full text with many other colorful illustrations available here.