Ploychaetes of family Pectinariidae are characterized by a gently tapering, tusk-shaped, very fragile sand tube. The tube is composed of a single layer of sand grains which are cemented with a proteinaceous glue (Watson 1928). The size and shape of the sand grains used increases as the worm grows and the shape of the tube is similar regardless of the sediment composition (Busch and Loveland 1975). Gordon (1966) describes Pectinaria gouldii as measuring approximately 4-6 cm in length. The tube is found in an oblique position just below the surface of the sediment. The head of the worm, located at the lower and larger end of the tube, has long paleae used for digging and long ciliated tentacles which bring sediment to the mouth. Some of this sediment may be rejected, but most of it is transported either through the worm's gut or between its body and tube to the surface of the mudflat where it is deposited as a small mound around the posterior end of the tube. The worm excavates small caverns that continually collapse and fill in with sediment from the sides and above.