Page 4 - Mariottinietal'09

8 P Mariottini, C Smriglio, A Di Giulio & M Oliverio

= Fehria van Aartsen 1988 – type species: Ginnania Type locality Coast of Posillipo, Naples, Italy.
taprurensis Pallary 1904, by original designation. Material examined Varazze (Genova), Italy,
Remarks The identity of Murex nebula Montagu 44°20’N 08°35’E, 20 m: 13 sh – San Vincenzo
1803, is still uncertain and a neotype designation (Livorno), Italy, 43°05’N 10°24’E, 34 m: 27 sh –
would be highly desirable to stabilize not only Anzio (Rome), Italy, 41°22’N 12°36’E, 50 m: 73
the species but also the genus name usage. In sh – Posillipo (Naples), Italy, 40°47’N 14°10’E, 3 m
any case, the traditional restricted usage, which depth: 1 sh – Marina di Camerota (Salerno), Italy,
ascribes to this genus a species morphologically 39°58’N 15°21’E, 30 m: 11 sh – Carini (Palermo),
similar to Pleurotoma laevigata Philippi 1836, is Italy, 38°12’N 13°28’E, 150 m: 2 sh – Off coast of
here assumed. There is no doubt that the spe- Libya, 110–150 m: 8 sh – Off coast of West Sahara,
cies herein studied (the B. menkhorsti-complex) 30–60 m: 7 sh.
belong in this genus. Conversely, we maintain Distribution Bela menkhorsti is known from
some doubts on the attribution to this same the entire Mediterranean Sea, and from the neigh-
group of Pleurotoma brachystoma Philippi 1844 bouring Atlantic.
and related species. Remarks Bela menkhorsti is characterised by a
biconical, elongate-fusiform, solid shell with a
At variance with most caenogastropods, where multispiral protoconch (530–540 µm max. diam.;
the protoconch-teleoconch boundary is clearly 2.0–2.2 whorls), indicating a planktotrophic lar-
marked by a discontinuity in sculpture, Bela val development. Outline of shell and teleoconch
shows a transition which appears more gradual. sculpture are indistinguishable from those of
In fact, the last protoconch part is often scultured B. zenetouae (and of the Pliocene samples: see
by collabral riblets which can mask the real below). On the contrary, the protoconch shows
boundary. We have marked in the apical views of useful diagnostic features at the species level.
the protoconchs (Figs 25b, 26b, 27b, 28b) the start The multispiral protoconch of B. menkhorsti is
of the teleoconch. completely different from the paucispiral one
of B. zenetouae (see below). Protoconch dimen-
Bela menkhorsti van Aartsen 1988 sions (diameter and number of whorls) are
(Figs. 1–8, 26) different between the Recent and fossil sam-
ples. Shell color is identical in B. menkhorsti and
Bela menkhorsti van Aartsen 1988a: 30–31, fig. 1. B. zenetouae.
Pleurotoma nana Scacchi 1836: 13, fig. 20, non
Deshayes 1835. Bela zenetouae (van Aartsen 1988)
Original description (Figs. 9–16, 27)
Pleurotoma nana Testa parva ovato-ventrosa, rufo-
fusca, linea pallidiore per medium ultimi anfractus Fehria zenetouae van Aartsen 1988a: 30–31, fig. 4.
decurrente; striis transversis exilissimis, costisque Original description
in lungum digestis; labro acuto. Alta lin: 3–3 ½. Ad Shell of a slender nearly biconical form. Whorls
Pausilipi oram. Fig. 20. 5, only slightly convex. Embryonic whorls: 1 peg-
Type material Lectotype (MNHN) from Posillipo like, smooth, rather convex initially. Sculpture:
(Naples, Italy, Figs. 2a, b), and two paralectotypes
in the same lot.

Figures 9a–16c Shells of Bela zenetouae (van Aartsen 1988). 9a–b, paratype AD13136, Haifa Bay, Israel, 50–65 m
[4.2×2.0 mm] (JvA). 10, Marechiaro-Posillipo (Napoli), Italy, 40°47’N 14°10’E, beached [7.7×3.5 mm] (CS-PM). 11,
Scilla (Reggio Calabria), Italy, 38°15’N 15°41’E, 40 m [4.4×2.4 mm] (CS-PM). 12, Sfax, Tunisia, 30 m [6.9×2.8 mm]
(CS-PM). 13, West Sahara, 30–60 m [7.6×3.0 mm] (FG). 14a, Egadi Islands (Trapani), Italy, 37°56’N 12°13’E, 50 m
[5.5×2.5 mm] (CS-PM). 14b–c, teleoconch sculpture and protoconch of the specimen in Fig. 14a. 15a, Sfax, Tunisia,
30 m [6.5×2.6 mm] (CS-PM). 15b–c, teleoconch sculpture and protoconch of the specimen in Fig. 15a. 16a–b, Scilla
(Reggio Calabria), Italy, 38°15’N 15°41’E, 40 m [2.1×1.2 mm] (CS-PM). 16c, protoconch of the specimen in Fig.
16a.