Stylifer, the operculum is lost, animal fixed by a large proboscis which forms a pseudopallium covering the whole shell except the extremity of the spire, parasitic on all groups of Echinoderms. Entosiphon, visceral mass still coiled; shell much reduced, proboscis very long forming a pseudopallium which covers the whole body and projects beyond in the form of a siphon, foot and nervous system present, eyes, branchia and anus absent, parasite in the Holothurian Deima blakei in the Indian Ocean.
The Tornaria larva offers a certain similarity to larvae of Echinoderms (sea-urchins, star-fishes, and sea-cucumbers), and when first discovered was so described.
Mailer's studies on the larval forms of Echinoderms and the discoveries of Vaughan Thompson were appreciated.
For edible purposes the most valuable of the Japanese echinoderms is the sea-slug or bche de mer (namako), which is greatly appreciated and forms an important staple of export to China.
De Pourtales pointed out in 1870; they consist of remains of deep-sea corals, serpulae, echinoderms and mollusca united Sands, gravels, muds, &c.