BRACHIOPODS or LAMP SHELLS
Although they resemble sea shells, brachiopods are not molluscs but a distinct group of very ancient lineage. The name lamp shell refers to the fact that, in typical forms, it resembles an ancient Roman lamp. The shelly valves of a brachiopod are not left and right as in a true shellfish, but upper and lower. To the inside of the lower valve is fastened delicate shelly loops which support the branchia, fleshy arms which combine the functions of breathing and directing small food particles to the mouth. Brachiopods were much more abundant in early geological times than they are at present. New Zealand species include a small red one (Terebratella inconspicua) very abundant under stones at low water on Rangitoto Island, Auckland, the much larger, 1½ in., Terebratella sanguinea common at Stewart Island, and the black brachiopod (Hemithyris nigricans), also mainly southern in distribution.
by Arthur William Baden Powell, Assistant Director, Auckland Institute and Museum.