Scaloid

Scaloids are circular scales with visible "cut-up" stripes. True scaloid scales can only be found on the extinct Crossopterygians. The inner layer of the scale is made of lamellar bone. On top of this lies a layer of spongy or vascular bone and then a layer of dentinelike material called cosmine. The upper surface is keratin. The coelacanth has modified scaloid scales that lack cosmine and are thinner than true scaloid scales.