Acteonidae, Bullinidae and Ringiculidae (Gastropoda: Heterobranchia) from the Plio-Pleistocene of the Philippines
Author
Helwerda, Renate A.
text
Zootaxa
2015
3990
2
197
220
journal article
39813
10.11646/zootaxa.3990.2.2
1740ec81-c55e-44ce-9a6d-cd62acd5d898
1175-5326
242947
BDF1BC11-4848-4858-99DC-0336A5FBEE2B
Ringicula bella
nov. spec.
(
Figures 23–24
)
Type
material.
Holotype
RGM
961.797 (
Type
locality).
Paratype
RGM
961.750 (
Type
locality) and
RGM
961.802 (Anda4).
Other material.
Anda1 (18)
RGM
961.798, Anda2 (22)
RGM
961.799, Anda3 (14)
RGM
961.800, Anda4 (50)
RGM
961.801, AndaDeVos (2)
RGM
961.803, AndaClif1 (1)
RGM
961.804, Tiep2 (3)
RGM
961.805, Tiep3 (5)
RGM
961.822, Tiep4 (8)
RGM
961.823.
Type
locality.
Anda1.
Derivatio nominis.
Pretty, adjective.
Diagnosis.
Shell moderately large; H
5.71 mm
,
W
3.85
mm; protoconch slightly elevated, 1.2 whorl, DP
0.33 mm
; nucleus moderately small, DN
0.17 mm
; teleoconch with spiral grooves; outer lip thick and crenulated; inner lip callused and with two nodules; columella callused and with two folds.
Description.
Shell rather high-spired, moderately large for its genus. Largest specimen has a total of 6.3 whorls, including a protoconch of 1.2 whorl. Protoconch rather small, smooth, weakly inclined. Teleoconch sculpted with thin, wavering spiral grooves and very weak, prosocyrt growth lines. Interspaces between spiral grooves decrease in width towards the base, whereas spiral grooves themselves increase in width towards the base. Spiral grooves intercalate along the whorls, increasing in number to 20–24 on the body whorl. Whorls convex, but not globose. Suture obscured by a narrow subsutural ridge, below which is a relatively broad groove. Aperture covered by thick callus, delineated by a rounded edge on the inner lip. Two, sometimes three rather small nodules present on parietal lip, lowermost nodule with a lamella extending into the aperture. Columellar lip bears two pronounced folds, lowermost fold crenulated. Outer lip thick, crenulated, with two subtle nodules present on the upper half of the lip. Exterior of the outer lip bears weak striations. Anterior and posterior sinus well-developed.
Differentiation.
Ringicula niinoi
Nomura, 1939
is similar in its size and sculpture, but its spire is less elevated, its parietal lip bears only one, larger, nodule and its outer lip is less thick.
Ringicula doliaris
Gould, 1860
is a variable, not well-described species. The specimens figured by
Habe (1950a)
,
Hori (2000)
and
Higo
et al.
(2001)
(
Higo
et al.
(2001)
figured the
holotype
) are slightly smaller, with a slightly less elevated spire, their spiral grooves are further apart, they have only one nodule on their parietal lip, their callus extends further onto the base and their outer lip is less thickened and smooth. The specimens figured by Willan (2010) are similar in shape, but smaller (height only
4–4.4 mm
), their spiral grooves are much further apart and they have only one nodule on their parietal lip.
Ringicula teramachii
Habe, 1950
is similar in its shape and sculpture, but slightly smaller (
holotype
height
4.9 mm
), its callus on the inner lip is thin and lacks a nodule and its outer lip is also much less thickened and not crenulated.