In this article we will discuss about the structure of Sea Butterflies with the help of a diagram.
1. Commonly known as “sea butterflies”.They are pelagic and are found along Atlantic coast swimming or attached to sea weeds.
2. Foot well developed, very prominent and is modified into a pair of wing-like epipodia or fin (pteropod) for swimming and springing from one place to other.
3. Shell hollow, conical, straight transparent and calcareous.
4. Mantle, gins, nephridia and operculum are absent.
5. Hermaphrodite and carnivorous.