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 10.11646/zootaxa.3990.2.2 1740ec81-c55e-44ce-9a6d-cd62acd5d898 1175-5326 242947 BDF1BC11-4848-4858-99DC-0336A5FBEE2B Acteon spec 4 ( Figure 12 ) Material. Tiep2 (1) RGM 961.770, Tiep5 (1) RGM 961.847. Characterization. Shell small, tall, with flattened sides; H 1.75 mm , W 1.12 mm; protoconch slightly elevated, 1.2 whorl, DP 0.71 mm ; nucleus small, DN 0.25 mm ; lower two-thirds of teleoconch whorls sculpted with fine punctuated spiral grooves, becoming stronger towards base; interspaces large, becoming smaller towards base; two separate weak punctuated spiral grooves present on upper one-third of first teleoconch whorl; suture weakly channeled with punctuated spiral groove broader than grooves on rest of whorl; aperture narrow; columella with weak single fold; umbilicus very narrow. Remarks. This species is distinguished from Acteon spec 1 by the presence of weak punctuated spiral ribs on the upper one-third of teleoconch whorls. All species within Acteonidae , of which material is well described and illustrated, differ from the species discussed here in their sculptural details.