Cuke: Holothuroidea. An apodida in the genus Chiridota (approximately 4" long). Each of those white dots is a dense pile of wheel ossicles, but otherwise the surface of this burrowing cucumber is largely ossicle free. [These are taken] frequently in trawl sampling, but usually as pieces rather than entire animals.
Comments and ID thanks to Don Cadien.
Golfball Reef, Palos Verdes, California