Note
Individual Axiothella rubrocincta Johnson on the Californian coast live in U-shaped tubes, feed on the surface of the sediment, attain densities of 100 m-2, attain lengths of 140 mm, have maximum oocyte diameters of 220 m and produce demersal larvae. Individuals from Washington populations live in vertical tubes, feed 10–15 cm below the sediment surface, reach densities of 5000 m-2, attain lengths of 60 mm, have maximum oocyte diameters of 385 m and brood their young in their tubes to at least the 7-setiger stage. Individuals from California have a scalloped posterior margin of the cephalic plate, while individuals from Washington have entire margins.