Cirsotrema

Zelaya, Diego G. & Güller, Marina, 2017, Undercover speciation of wentletraps (Caenogastropoda: Epitoniidae) in the Southwestern Atlantic, Zootaxa 4286 (1), pp. 41-69 : 58-59

“ Cirsotrema ” georgeanum nomen novum

( Figure 10 )

Scalaria fenestrata Strebel, 1908: 63 –64, pl. 4, fig. 61a–d (non Meneghini in de Stefani, 1875 nor Wöhrmann, 1889) Cirsotrema fenestrata: Powell, 1951: 114 ; Zelaya, 2005: 121

Type locality. 54°11’ S 36°18’W, Cumberland Bay , South Georgia 252–310 m.

Type material. Two syntypes (one syntype at SMNH type-918: Fig. 10 A; the other syntype at ZMH 3139: Fig. 10 B, C).

Known distribution. Only known from South Georgia.

Etymology. The name of the species refers to its provenance.

Remarks. Scalaria fenestrata Strebel, 1908 appears at present as a junior (primary) homonym of Scalaria fenestrata Meneghini in de Stefani, 1875 and Scalaria fenestrata Wöhrmann, 1889 . Due to the above, “ Cirsotrema ” georgeanum is here proposed as a replacement name for Strebel’s species.

In shell morphology, “ Cirsotrema ” georgeanum resembles “ Cirsotrema ” magellanicum ; both species reach large sizes, and are sculptured with widely separated, lamellate axial ribs, with low but strong spiral elements in the interspaces of axial sculpture, and with a prominent spiral cord at the base. In fact, Brown & Neville (2015) suggested that both are probably synonyms. However, “ Cirsotrema ” georgeanum differs from “ Cirsotrema ” magellanicum by being slender, with whorls separated by a deeper suture, axial ribs with prominent coronations, and by lacking the auriculate peristome that is present in “ Cirsotrema ” magellanicum . Given these differences, both taxa are here regarded as distinct.

Figures

FIGURE 10. “ Cirsotrema ” georgeanum new name, shell. A. Syntype of Epitonium fenestratum (SMNH type- 918). B, C. Syntype of Epitonium fenestratum (ZMH 3139). C. Detail of teleoconch sculpture at the suture. Scale bars: A, B = 10 mm; C = 2 mm.