TYPE SPECIES. — Flexopteron philippinensis Shuto, 1969, Late Miocene, Philippines (by original designation).

REMARKS

There are currently two known Recent species of Flexopteron: F. primanova (Houart, 1985) from Madagascar and F. poppei (Houart, 1993) from the Philippines. Two other Recent species were included in Flexopteron by Merle et al. (2011): Poirieria (Paziella) tanaoa Houart & Tröndlé, 2008 from the Marquesas and Paziella (Flexopteron) sp. from the Philippines. Paziella (Flexopteron) sp. (Merle et al. 2011: pl. 141, figs 12a, b) is a species of Coralliophilinae, probably in the genus Lamellatiaxis Habe & Kosuge, 1970.

We do not accept the classification of Poirieria (Paziella) tanaoa in Flexopteron by Merle et al. (2011). The radula characters are not known for P.tanaoa but its shell is quite different from that of species of Flexopteron, being more elongate with fewer spiral cords, a relatively smaller aperture and a longer siphonal canal, shell characters that are closer to Paziella than to Flexopteron. In fact, P. tanaoa strongly resembles the specimen illustrated by Merle et al. (2011: pl. 144, figs 4a, b) as Crassimurex (Eopaziella) capita (Philippi, 1844) from the Late Oligocene of Europe. Currently we do not see any reason to remove P. tanaoa from Paziella.

The shell morphology of Flexopteron akainakares n. sp. is close to F.primanova Houart, 1985 but the species has different radula characters and is here only tentatively assigned to this genus.

We have now used Flexopteron as a full genus since its radular morphology (Fig. 14 D-F) is different from Poirieria (Marshall & Houart, 1995).