Ringicula caelestis

Helwerda, Renate A., 2015, Acteonidae, Bullinidae and Ringiculidae (Gastropoda: Heterobranchia) from the Plio-Pleistocene of the Philippines, Zootaxa 3990 (2), pp. 197-220 : 212

publication ID	https://doi.org/ 10.11646/zootaxa.3990.2.2
publication LSID	lsid:zoobank.org:pub:BDF1BC11-4848-4858-99DC-0336A5FBEE2B
DOI	https://doi.org/10.5281/zenodo.6116541
persistent identifier	https://treatment.plazi.org/id/03FA878C-951F-FE45-FF26-E1680211CDAA
treatment provided by	Plazi
scientific name	Ringicula caelestis
status

Treatment

Ringicula caelestis View in CoL nov. spec.

( Figures 29–30 View FIGURE 29 – 33. 29 )

Type material. Holotype RGM 961.824 (Type locality), paratype RGM 961.752 (Tiep2)

Other material. Anda1 (24) RGM 961.806, Anda2 (17) RGM 961.807, Anda3 (11) RGM 961.808, Anda4 (10) RGM 961.809, Anda6 (1) RGM 961.810, AndaDeVos (4) RGM 961.811, Roxas (25) RGM 961.812, Tiep2 (19) RGM 961.813, Tiep4 (2) RGM 961.815, Tiep5 (3) RGM 961.816.

Type locality. Anda1.

Derivatio nominis. Heavenly, adjective. Named after the miniature rainbows that the microscope lamps tend to project onto the shells.

Diagnosis. Shell very small; H 1.71 mm, W 1.20 mm; protoconch simple, 1.2 whorl, DP 0.22 mm; nucleus small, DN 0.09 mm; teleoconch with distinct grooves; aperture narrow; outer lip callused, smooth, projecting beyond columella; inner lip callused, with one lamella; columella with two folds.

Description. Shell moderately elevated, very small for its genus. Largest specimen has a total of 4.4 whorls, including a protoconch of 1.2 whorl. Protoconch small, smooth, inclined. Teleoconch sculpted with spiral grooves, which are very weak on the first teleoconch whorl, but become distinct after that. Their interspaces are about twice as wide as the spiral grooves themselves. Straight growth lines are visible within spiral grooves. Spiral grooves number 14 on the body whorl. Whorls convex, but not globose. Suture canaliculate. Aperture covered by thick callus, extending onto the base. Upper half of parietal lip is thickened and connected to a lamella extending into the aperture. Columellar lip bears two smooth folds, with the upper one less developed than the lower one. Outer lip thick, with a swelling present on the middle of the lip. Exterior of the outer lip bears weak striations. Anterior and posterior sinus rather shallow.

Differentiation. Ringicula caelestis nov. spec. is set apart from most Ringicula species by its very small size. Ringicula kurodai Takeyama, 1935 is also quite small, but it is more elongate and it has a strong nodule on the parietal callus. Ringicula prismatica de Folin, 1868 is similarly small, but more elongate and it only has spiral grooves on the base.