Triforis tricincta Dunker, 1882

Albano, Paolo G. & Bakker, Piet A. J., 2016, Annotated catalogue of the types of Triphoridae (Mollusca, Gastropoda) in the Museum fuer Naturkunde, Berlin, with lectotype designations, Zoosystematics and Evolution 92 (1), pp. 33-78 : 60-61

Taxon classification Animalia Caenogastropoda Triphoridae

Triforis tricincta Dunker, 1882 Figure 28

Triforis tricincta (new name for Triforis cingulata Dunker, 1860)

Triforis cingulata Dunker, 1860: 236; figured in Dunker 1861: 10, tab. 2, figure 1.

Triforis tricincta Dunker, 1882: 109.

Type specimens.

Holotype SMF no. 304813 (designated by Janssen, 1993).

Type locality.

Japan.

Original description.

T. testa turrita, unicolore fusca, anfractibus planis 14 (usque ad 16?) costulis duabus crassioribus et una tenuiore intermedia cinctis, interstitiis clathratis; basi planata; peristomate subquadrato; rostro brevi. - Alt. 9, lat. 2½ mill.

Diese Art ist durch ihre Skulptur ausgezeichnet. Die Windungen sind von zwei stumpfen glatten Kielen oder Rippchen umgeben, in dem Zwischenraum aber befinden sich zarte erhabene Längsstrichelchen, die von einer feinen Querlinie durchschnitten werden, wodurch eine gegitterte Oberfläche entsteht. Die Naht ist deutlich.

Translation.

Slender shell, of brown uniform colour. Fourteen flat whorls (to 16?) with two large cords and a fine further cord in the middle, space between cords with a cancellate sculpture. Flat base [but it refers to a subadult specimen, illustrated in 1861], subquadrate peristome [again may be due to the description of a subadult specimen], short siphonal canal. Height 9, width 2.5 mm.

This species is characterized by its sculpture. The whorls bear two blunt smooth cords, between them there are longitudinal riblets, which are intersected by a fine thread, creating a cancellate sculpture. A clear suture is visible.

Diagnosis.

Large and slender shell, the illustrated specimen (Fig. 28 A-C) is 11.6 mm. Teleoconch of 15 whorls, which have three smooth spiral cords; the second is thinner than the other two. A fine suprasutural smooth cord is also present. The last whorl has a fourth smooth cord, the base has a fifth smooth cord. On the peristome, an additional spiral cord develops between the second and the third. A large posterior notch is present. The apex is not present in the holotype ( Janssen 1993) nor in the Japanese specimens preserved in Berlin. The specimen from Dutch Bay (Sri Lanka) has a worn apex, but it can be recognized to have several whorls (multispiral protoconch), probably with two spiral keels and axial riblets. Colour brown.

Remarks.

This species was first described by Dunker in 1860 as Triforis cingulata . In 1882, Dunker introduced the new name Triforis tricincta ; although he did not specify the reason, Triforis cingulata was indeed a preoccupied name by Triphoris cingulatus A. Adams, 1854. The holotype preserved in the Senckenberg Museum is a worn subadult specimen, lacking apex and with a very worn sculpture ( Janssen 1993).

The collection in Berlin hosts four lots labelled as Triforis cingulata or Triforis tricincta : three coming from Japan (Enosima, Sakura) and one from Dutch Bay (Sri Lanka). All Japanese specimens are in poor condition, but the specimens from Dutch Bay are quite nice and deserved illustration to better depict the diagnostic characters of this species.