Fulton named his submarine after a marine mollusk, the chambered nautilus. Nemo created an airship named the "Nautilus" within the game. It is a fork of GNOME Files (formerly named Nautilus). The chalk contains many fossils such as ammonites and nautilus. Illithids' primary ship type is the nautiloid, a 35-ton craft resembling a nautilus. The captain later introduces himself as Nemo, master of the "Nautilus". Implosion depth for nautilus shells is thought to be around . One includes nautilus and most fossil nautiloids. American composer and commentator Deems Taylor wrote a cantata entitled The Chambered Nautilus in 1916. The updated Nautilus 3.32 file manager now supports favoriting files. American defense company Northrop Grumman proposed developing a more advanced prototype of Nautilus, Skyguard. The first such submarine was USS "Nautilus" commissioned in 1954. Madsen built three submarines&colon; "UC1 Freya", "UC2 Kraka" and "UC3 Nautilus". Robert Fulton then improved the submarine design by creating the "Nautilus". In 1800, the French Navy built a human-powered submarine designed by Robert Fulton, the "Nautilus".