Orbitremites derbiensis blastoid collected from Carboniferous sediments in Richmond, Yorkshire, UK. Orbitremites belong to the class Blastoidea and they are a type of echinoderm. They resemble their distant relatives, the crinoids, being attached to the sea floor by a stalk, trapping food with tentacle like appendages. These specimens are available in two sizes: Small measures between 0.5 - 1 cm and Large measure between 1 - 1.5 cm in diameter. Supplied in small plastic bags with an information label.