The statoconia of goldfish, ray, frog and pigeon were investigated by the use of light and electron microscopes. Concentric lamellation of daily ''growth rings'' reported earlier was observed. This lamellation was formed by alternating slow-growth bands and fast-growth bands. The former contains more protein matrix than the latter. The ray statoconia are comprised of grains of sand (exogenous) and round crystals with internal lamellation (endogenous?). The frog statoconia are made of numerous crystals which contain a large amount of protein matrix as in the mammalian statoconia.