Alcithoe jaculoides is a species of large sea snail, a marine gastropod mollusc in the family Volutidae, the volutes.
The length of the shell attains 188 mm, its diameter 70 mm.[1]
(Described as Alcithoe calva) The shell is very large, narrow, and elongated, comprising 8½ whorls. The protoconch has a scaphelloid shape. It is moderately large, consisting of 2½ smooth whorls. The remaining whorls are smooth and devoid of sculpture, except in rare instances where the spire whorls are faintly shouldered, showing traces of axial ribs.[2]
The spire is tall with slightly convex whorls. It measures approximately half the height of the aperture, The body whorl is elongate and sub-cylindrical, gradually contracted below to a rounded fasciole, not marked off by the usual ridge. The aperture is long and rather narrow with a shallow notch below. The outer lip is thickened and reflexed above, ascending about one-third the height of the penultimate whorl. The columella is straight, tapering to a sharp point below, with six comparatively weak, very oblique plications; the uppermost being more or less rudimentary. There is no projecting callus plate. The inner lip is spread as a thin glaze broadly over the body whorl.
The color of the shell is pale buff, ornamented with indistinct, irregular light brown zigzag lines. The interior of the aperture is pinkish-fawn.
This species is found only along the coast of North Island, New Zealand. [3]