eversible

“The male organs consists of two testes which connect to sperm ducts that unite and lead to an eversible copulatory cirrus.”

Platyhelminthes

“Nemertines however, lack a protective cuticle or exoskeleton as well as stalked eyes, but have a characteristic eversible proboscis.”

Down with phyla! (episode II) - The Panda's Thumb

“Osmaterium - ia: fleshy, tubular, eversible processes producing a penetrating odor, capable of being projected through a slit in the prothoracic segment of certain Papilionid caterpillars, and from openings elsewhere in the bodies of other forms.”

Explanation of Terms Used in Entomology

“Red in, well, harpoon-like proboscis and, uh ... eversible stomach.”

Pharyngula

“In case you don't know, caecilians have sensory tentacles, sometimes have protrusible eyes, sometimes lack eyes entirely, often exhibit sophisticated parental care [maternal skin-feeding is going on in the middle image above], are incredibly long-bodied yet often lack tails, sometimes possess large, anatomically complex, eversible male sexual organs, and so on and so forth.”

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