Caudal luring species and allegedly by two lizards, though other interpretations (e.g., distraction) seem more plausible for the lizards. Caudal luring also occurs in a shark, the tasselled wobbegong, "Eucrossorinus dasypogon" and very likely in the pelican eels, "Eurypharynx", which possess a bioluminescent tail tip. The behavior is associated with sedentary predators whose diets include animals susceptible to a worm-like (or fish-like, in the case of "Eucrossorinus" and perhaps "Eurypharynx") luring appendage. Snakes generally lure small ectotherms (e.g., frogs and lizards), although luring of birds has been demonstrated (Spider-tailed horned viper) and luring of insectivorous mammals is suspected. Caudal luring occurs most
Operculum (gastropod) to push into the substrate in a leaping form of locomotion. Virtually all pulmonate snails are inoperculate, i.e. they do not have an operculum, with the exception of the Amphiboloidea. However, some terrestrial pulmonate species are capable of secreting an epiphragm, a temporary structure that can in some cases serve some of the same functions as an operculum. The epiphragm may be distinguished from the true operculum by its homogeneity and want of growth marks. In ammonites (extinct shelled cephalopods), a calcareous structure known as the aptychus (plural aptychi) existed. When these were first described they were thought to be