Seven National Oceanic and Atmospheric Administration and United States Geological Survey expeditions employed manned submersibles or remotely operated vehicles to explore deep-sea coral and cold seep habitats in the northern central Gulf of Mexico continental slope, off Mississippi and Louisiana. Ten species of echinoids and 21 species of holothurians were collected and/or documented by still photography or videography in a relatively small area, in depths of 309–2549 m. New information on ecology, behavior, and distribution of echinoids and holothurians is provided. A new genus name is proposed to replace Meseres Ludwig, 1893, which is preoccupied. Myriotrochus ahearnae, a new species of apodous myriotrochid holothurian, is described.
