The mollusc phylum consists of seven orders of multiply, plateless, veneer, tepedope, gastropods, bivalves, and cephalopods
Plateless is one of the molluscs, divided into fur shellfish and crescent shellfish, about 200 species. Plateless is the most primitive group of molluscs, with worm-like bodies and no shells. The mantle membrane is developed, wrapped around the outside of the body, the surface layer and various calcareous bone needles. There is a groin in the center of the ventral side, and there is a small cilia foot in the groove, which has a motor function. The mantle cavity is located behind the body, with a pair of gills in the cavity, and the anus and genital foramen pass through the genital cavity. Common species are fur shells, crescent shells, and dragon hairpins.
Representative animal: Dragon Girl Hairpin
Latin name: Proneomenia
Species classification: Mollusc Phylum Mollusca Plateless Aplacophora
The individuals of the Dragon Lady are smaller and slender, with a length of about 15.0 mm and a width of about 1.0 mm. The head of the dragon girl is separated from the body by a pronounced contraction, the mouth is located directly in front of the head, and the midgut sac area is slightly wider than the midgut area. The dragon girl has a yellowish-white overall appearance, the whole body is covered with a large number of fine bone needles, and the bone needles in the midgut area are relatively upright, and the bone needles are lanceolate. The foreguct and midgut areas of the dragon hairpin are separated by a shallow ravine. The mouth of the dragon hairpin is located on a narrow disc, and the posterior coat cavity of the body is light red, with an anus and gills inside. The mouth of the dragon hairpin is located on a narrow disc, and the posterior coat cavity of the body is light red, with an anus and gills inside.