Nautilus is a marine mollusk with a thin and light shell and a spiral coil. The surface of the shell is white or milky white, radiating long lines from the umbilical cord of the shell, smooth and delicate, mostly reddish brown. The whole snail shell is as smooth as a disk and shaped like a parrot's mouth, hence the name "Nautilus".

Nautilus has experienced hundreds of millions of years of evolution on the earth, but its shape and habits have not changed much. Known as the "living fossil" in the ocean, it has high value in studying biological evolution and paleontology, and also occupies a place in modern bionic science.

Nautilus has a curly pearl shell, which is smooth and curly. Shells can reach 26.8 cm, but adult nautilus is generally less than 20 cm.

Introduction to Two Wan Li under the Sea:

Two Wan Li under the Sea is the second part of Verne's famous trilogy. This collection contains many features of Verne's science fiction and is fascinating. In the process of reading, readers will unconsciously follow the author's ideas, travel around the world and feel the magic and scientific power of nature.

The novel mainly tells the story of naturalist Pierre Aronnax, his servant Conseil, harpooner Ned, and the captain Nemo of the submarine Nautilus.