Gemmula rosario: Shell medium sized, thick, elongate fusiform, turrated and with 10 volutions of teleoconch. Protoconch small, globous, brown, smooth and with 2 volutions. Spire very high, narrow and with undeep suture. Whorl white with brownish tint. Four primary spiral ridges on penultimate whorl brown and sharp. First primary one most eminent, second one tortulous or gemmate; third and fourth ones relatively weak. About 20 spiral ridges visible on last whorl, of which third to sixth ridges run on shoulder of it. Third and fourth ones correspond peripheral ridges. Axial striae running oblique to spiral ridges. Posterior sinus deep, narrow, V-shaped and touching second spiral ridge. Columella narrow and twisted. Siphonal tube long and narrow. Aperture subrhombic with thin outer lip; inner surface of aperture white and lustrous.
Holotype: Shell 44.6mm high and 12.4mm wide, stored in the writer's collection presented by HAYASHI,
Locality: Kii Channel, Japan, 100-150m deep.
Remarks: This species may be nearest murrayi POWELL but is distinct by narrower spire, shorter siphonal tube and by stronger third - post-third spiral ridges.

Gemmula rosario: Shell length about 4,5 cm, aperture 0,38-0,45 total length, suture not distinctly channelled; subsutural cord bicarinate, crest of second ridge very slightly bifid; peripheral cord rather weak,'gemmae relatively small and close, bifid, 36-48 on penultimate whorl; each gemma terminates below in a short tail which subtends a slight punctation; shoulder sulcus very shallow, wider than subsutural cord; basal periphery of body whorl as in gilchristi. Colour uniform or mottled yellowish-brown. Protoconch diameter 0,8-1,1 mm. Radula without rachidian plates.
Description (Natal population): Shell with aperture 0,38-0,45 of total length; spire orthoconic to slightly cyrtoconic; sutures not distinctly channelled; about ten teleoconch whorls. Subsutural cord bicarinate with a thin, non-cristate lira at suture and a main ridge whose crest is faintly bifid, the two ridges usually being separated by a fine intervening thread. 'Peripheral cord rather weak, sometimes not even projecting to level of actual periphery of body whorl; gemmae relatively small and close-set (numbering 36-48 on penultimate whorl) and crenulating edges of shoulder cord; each gemma ends below in a short prosocline 'tail' which subtends a slight punctation. Shoulder sulcus barely impressed, wider than subsutural cord, with 4-5 thin spiral lirae. Basal periphery of body whorl bearing 4 main spiral ridges, 1-2 of which appear on the spire whorls; intervals each with a weaker ridge and several fine spiral striae. Rostrum with numerous spiral threads, becoming progressively finer anteriorly, initially alternately weaker and stronger, with one ridge at base of rostrum markedly stronger than the others. Growth striae relatively weak. Anal sinus typical. Colour uniformly moderate yellowish-brown. Protoconch conical, 3,5 whorls, axial ribs commencing on penultimate whorl, about 19 on last whorl; translucent brownish, diameter 0,8-0,9 mm. Dimensions (Durban shells): 44,8x14,2 mm, 41x12,5 mm, 38,5x13,1 mm. Japanese specimens: 47,1 x 14,7 mm, 40,3 x 12,1 mm. Radula consisting of marginal plates only.

Gemmula rosario: Japan to Natal.