Triphora algoensis Thiele, 1925

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 : 36

Taxon classification Animalia Caenogastropoda Triphoridae

Triphora algoensis Thiele, 1925 Figure 3

Triphora algoensis Thiele, 1925: 128-129 (94-95), plate XXII (X), figure 19.

Type specimens.

Lectotype: ZMB/Moll no. 109270a, from Station 100 (Francis Bay), here designated. Paralectotypes A-D ZMB/Moll no. 109270b-e.

Type locality.

"Stationen 81 [Groβe Fischbucht], 95 [Cap Agulhas], 100 [Francis-Bucht], 101 [Algoa-Bucht]" (South Africa).

Original description.

Schalen von denselben Stationen 81, 95, 100 und 101 sind denen der vorigen Art [ Triphora capensis ] in Größe und Skulptur ähnlich, aber durch folgende Merkmale unterschieden: die Form ist etwas schlanker, die Anfangswindungen zeigen bereits deutliche Knoten und zwar in 2 Reihen, zwischen die sich alsdann eine dritte einschiebt, die 12½ Windungen der abgebildeten Schale sind nicht gewölbt, die letzte unten kantig und nur mit 3 Reifen unter der Kante besetzt, die Mündung ist niedriger, der Mundrand etwas flügelartig vorgezogen, oben zurücktretend, die untere Rinne etwas gebogen. Färbung braun. Auffällig ist allerdings die ganz gleiche Verbreitung, doch scheinen die angegeben Merkmale dagegen zu sprechen, daß beide Formen zu derselben Art gehören.

Translation.

Shells from stations 81, 95, 100 and 101 are similar to the ones of previous species [ Triphora capensis ] in size and sculpture, but distinguished by the following features: the shape is slightly slimmer, the protoconch whorls already show two rows of tubercles, between those the third row develops, the 12½ whorls of the shell are flat, the last whorl is angulated and bears three cords under the edge, the aperture is shorter, the peristome has a winged shape, with a developed posterior sinus, the siphonal canal bent slightly. The colour is brown. The overlap in distribution is remarkable, however the described characters show that both forms do not belong to the same species.

Diagnosis.

Lectotype height 8.8 mm. Conical shell, with very flat sides. Teleoconch of nine whorls, which have three tubercled spiral cords: the second develops later and is fully visible on the third whorl. A fourth suprasutural smooth cord is also present. The base has two further smooth spiral cords. Peristome simple, without bifurcating cords. A deep posterior siphonal canal is present. Paucispiral large apex of three whorls; the transition to teleoconch is difficult to spot. The protoconch is ornamented by two strong tubercled spiral cords. Colour light brown, apex slightly darker.

Remarks.

The specimen figured in Thiele’s work lacks the lower part of the last whorl near the aperture, like the best syntype available, which is here designated as lectotype. Station 81 is probably located in Agulhas Bank and not in Angola as the geographic coordinates would suggest ( Kilburn 1996) (see Materials and methods).