Mastonia cingulifera (Pease, 1861b). Length, 7 mm; diameter, 2 mm. Shell: conic-elongate inflated; with two prominent beaded spirals and a threadlike middle spiral; yellow lineated with red-brown. Spire: protoconch acuminate, of four dark brown whorls, the apical smooth, remaining three unicarinate with fine axial ribs extending to the suture; teleoconch of ten inflated whorls; suture deep, wide. Sculpture: three beaded spirals of which the apical and abapical are prominent, the apical row of circular beads separated by shallow interspaces one-quarter the diameter of the beads and in the later whorls delineated abapically by a spiral thread; middle row threadlike; abapical row of small, spirally elongate beads; last whorl with four granular spirals, the rows progressively smaller and more obsoletely beaded; siphonal canal with a smooth cord bounding it. Aperture: subcircular; anterior canal not completely closed, short, sharply recurved; posterior canal a notch. Color: apical spiral red-brown, abapical yellow and base with three brown spirals; apical whorls white. Animal: exposed parts orange-red speckled with white.
This triphorid is both ubiquitous and abundant in Hawaiian waters. It is the most commonly occurring triphorid in shallow water, found in tide pools and shoreward of fringing reefs; it is less common in coral communities to depths of about 15 m. Shells are abundant in beach drift and are occasionally found in sediments to depths of 65 m.
M. cingulifera occurs throughout the Indo-West Pacific, from Mauritius (Viader, 1937) to New Caledonia and southern Japan (Kuroda and Habe, 1952), and has been reported from Holocene sediments from Enewetak, Marshall Islands and Saipan (Ladd, 1972).