What is "elasipodida"

Elasipodida is an order of sea cucumbers. They are somewhat unusual in appearance, in comparison with other sea cucumbers, having numerous appendages, including conical papillae and leaf-like tentacles. Although many species are benthic, a number are pelagic, and may have their appendages modified to form sails or fins. Most members of the order inhabit deep-sea environments, like Enypniastes.