Lampocteis is a monotypic genus of comb jellies, the only genus in family Lampoctenidae. The sole species in this new genus is Lampocteis cruentiventer, the bloodybelly comb jelly. This ctenophore was first collected in the Pacific Ocean off the coast of San Diego, California, in 1979. It was described to science in 2001. Two morphological differences separating it from previously known comb jellies warranted the naming of a new family for this animal.
This mesopelagic jelly ranges in color from deep red, purple, or black to pale purple. The deep color of its belly may mask the animal's bioluminescence to hide it from potential predators. Its "combs," rows of cilia on its body, have a sparkling iridescence. Specimens examined have ranged between 1.5 and 16 centimeters in length and 1.2 to 10 centimeters in width. Comb jellies do not sting and recent studies have shown that they are not actually cnidarians. In fact scientists do not know what the comb jellies ancestors are.