Range — Most warm seas and abundant in the Tertiary, back to the Paleocene. The genus is abundantly represented in the Tertiary of both Europe and North Amerca, but the greatest representation is now in the Indo-Pacific. Very few species still exist in Caribbean-Panamic waters, and now there are none in Mediterranean and West African waters, where Gemmula is replaced by Fusiturris.

Shell rather large, 24-88 mm., elongate-fusiform, with tall spire and long straight unnotched anterior canal. Protoconch tall, conical polygyrate and axially costate. Adult sculpture of spiral keels and cords, the peripheral keel mostly double, often flanged and always studded with gemmules, often cog-like in vertically fused pairs. Sinus deep and narrow, on the peripheral carina. Operculum leaf-shaped, with a terminal nucleus. Radula consisting either of a pair of wishbone-shaped marginals only (G. hombroni), or with the addition of a central tooth, which may be vestigial (G. congener diomedea), to fully formed, unicuspid, with a large broad base (G. gilchristi).
Coloration, usually with peripheral dots of brown alternating with the gemmules and sometimes with the addition of brownish spiral bands and zones.

Diagnosis: Shell small, up to 25 mm, narrowly turreted with up to nine teleoconch whorls, with moderately long, straight siphonal canal, with prominent to strongly angular shoulder. Suture from shallowly impressed to narrowly channelled. Protoconch paucispiral of 1.5 2 whorls smooth except for few arcuate axial ribs near transition to teleoconch. Subsutural cord from very weak to strong, occupying most of subsutural ramp, subdivided into smaller adapical ridge and larger abapical one. Subsutural ramp distinctly concave (G. kindsiana) with few small spiral cordlets, or limited to rather shallow groove between subsutural and peripheral cords (G. closterion). Peripheral cord markedly stronger than subsutural one, forming prominent shoulder angle, gemmate; gemmae orthocline, rather broadly spaced, very shallowly bifid, 16-22 on last whorl; intervals with two feeble spiral threads. Peripheral cord sometimes bordered by narrow cordlets ad- and abapically. Shell base with three strong major cords. Siphonal canal with distinct, uniform, more closely spaced and much weaker cords. Anal sinus narrow and deep on peripheral cord. Aperture (without canal) 0.21-0.30 of SL. Ground colour from uniformly greyish to light orange, with lighter peripheral cord. Radula (G. closterion) comprising about 40 rows of teeth. Marginal teeth dúplex, narrow, accessory limb inserted in shallow socket of major limb; major limb forming blunt cusp at this insertion, central formation weak with short blunt cusp.
Remarks: Only two described species are attributed here to this previously very species-rich genus. Based on the exon capture analysis, they form long branches, and do not always cluster together (Zaharias et ai, 2024). Both of them are characterized by a narrow, small shell with gemmate peripheral cord. Our sequenced specimens of Gemmula closterion originate from south-ern New Caledonia and from greater depths (405-530 m) than the type specimens (Indonesia, Tanimbar Islands, 146-239 m) and differ in their somewhat broader shell. We attribute them to G. closterion with some reservation, based on their general similarity and paucispiral protoconch, which is uncommon in Turridae. One still unnamed species from the bathyal depths ofjapan (W of Amami Is.), sister to G. closterion in the COI tree, is also here attributed to Gemmula, a decisión also supported by the overall conchological similarity and the paucispiral protoconch of this species.

Distñbution: Shallow water (40- 70 m) of Baja California, Tehuantepec Gulf (G. hindsiana), New Caledonia and Indonesia, in 146 530 m (G. closterion); Japan, in 345 m (Gemmula sp. 01).