Nerita cf. funata Dujardin, 1837

Plate 1 E 1 -E 3

cf. * Nerita funata Dujardin 1837: 281, pl. 19, fig. 14.

? Nerita Plutonis Bast. —Bronn in Reiss 1862: 33.

? Nerita Plutonis Bast. — Mayer 1864: 63, 93.

cf. Nerita (Theliostyla) funata Dujardin, 1837 — Glibert 1949: 69, pl. 4, fig. 8.

Santa Maria material examined. Maximum height 4.0 mm, width 6.0 mm. DBUA-F 917-1 (1), Ponta do Castelo, Santa Maria Island, Azores, Touril Complex, Lower Pliocene.

Description. Apical fragment with completely flattened spire. Teleoconch bearing about 22 subequal rounded ribs, slightly narrower than their interspaces, shoulder cord slightly strengthened.

Discussion. Mayer (1864: 63) recorded two specimens from Bocca do Cré (= Cré), Santa Maria Island, without indicating their size. The Azorean material is very incomplete, but clearly represents a Nerita species of the Theliostyla M̂rch, 1852 group. Two species occurred along the French Atlantic Frontage during the Miocene. Nerita plutonis de Basterot, 1825, from the Lower Miocene, has relatively coarse cords of irregular strength and N. funata Dujardin, 1837, from the Middle Miocene, has finer, subequal cords. Lozouet et al. (2001: 20) considered the Lower Miocene records of N. funata in Cossmann & Peyrot (1917: pl. 7, figs. 77-82) to represent N. plutonis .

The fragment at hand from Santa Maria Island, has numerous subequal ribs more closely similar to those seen in N. funata than N. plutonis . However, we hesitate to make a definitive identification based on this very incomplete specimen. The historical Azorean specimens identified by Bronn in Reiss (1862: 33) and Mayer (1864: 63, 93) as N. plutonis are likely to represent the same species.

This group of Nerita species with spiral cords is not represented in the Pliocene Mediterranean. Today, the group is represented in the eastern Atlantic by N. senegalensis Gmelin, 1791, distributed from the Cabo Verde Islands to Angola, whereas in the western Atlantic a total of five species are reported, four of them from Bermuda, the Gulf of Mexico and the Caribbean ( Nerita fulgurans Gmelin, 1791; Nerita peloronta Linnaeus, 1758; Nerita tessellata Gmelin, 1791; and Nerita versicolor Gmelin, 1791), and one species endemic to Brazil ( Nerita chlorostoma Lamarck, 1816). Nerita senegalensis differs in having flattened cords of irregular width, separated by narrow grooves.

Distribution. Lower Pliocene: Atlantic, Santa Maria Island, Azores (?Bronn in Reiss 1862;? Mayer 1864; this paper).