C. flavidula is readily recognized by 1) slender claviform shell up to 70 mm in height, 2) teleoconch whorls subangular, with slightly concave shoulder slope and faint subsutural margining, 3) anal sinus moderately deep, openly U-shaped and 4) sculpture of 10-12 low collabral ribs overridden by well spaced spiral cords; fine spiral threads occur on the shoulder slope and between the cords.
DISTRIBUTION AND HABITAT. The species is distributed from the Red Sea to Australia and northward to Japan. It is a sublittoral element occurring in silty and muddy substrates. FOSSIL RECORDS. Late Miocene of Indonesia; Pliocene of Indonesia, Taiwan and Japan; Quaternary of Indonesia.

Shell large, up to 56 mm, narrow, very high spire, solid. Protoconch small, smooth, conical, 2 whorls, 0.58 mm high, 0.68 mm wide. Up to 12 teleoconch whorls. Suture thin, indistinct, nearly straight, slightly channeled on lower whorls. Sculpture complex, dominated by low axial ribs, 15 on penultimate whorl, 13 on body whorl, angled to left. Final rib of body whorl swollen into a varix. Ribs begin about 1/4 way down the whorl, reach maximum above midwhorl, taper off but.reach lower suture, extend well down body whorl, but not to tip. Ribs crossed by prominent series of triangular spiral cords, 7 on penultimate whorl, 15-20 on body whorl, smaller cords may be between larger ones. Numerous spiral striae occur over entire whorl surface. Low nodules occur where spiral cords cross axial ribs. Numerous fine axial growth lines also present. Outer lip thin, slightly incurved. Sinus subsutural, moderately deep, upper margin does not come forward. Moderately strong callus present. Aperture elongate-oval, relatively narrow, deep. Columella smooth, thin, slightly convex. Anterior canal moderately long, moderate width and depth, tip reflected upwards, slightly notched. Colour uniform light brown or yellowish with a single purple band across the body whorl (see description of holotype of P. flavidula below), nodules and aperture lighter.

Type localities: Red Sea. Distribution: 18-320 m depth, Indo-West Pacific; Dirk Hartog Island, Western Australia to Moreton Bay, Queensland.