Darwin and the cirripedes: Insights and dreadful blunders.

Charles Darwin's favorite animals were cirripedes (barnacles). Indeed, he worked intensively on cirripedes during the years he was maturing his thoughts regarding his theory, which eventually led to the publication of The Origin of Species. Here I present some of Darwin's achievements in the morphology, systematics and biology of these small marine invertebrates, and also, in light of our present knowledge, some mistakes he made.