Mitrolumna Bucquoy, Dautzenberg & Dollfus, 1883 : 121

Amati, Bruno, Smriglio, Carlo & Oliverio, Marco, 2015, Revision of the Recent Mediterranean species of Mitromorpha Carpenter, 1865 (Gastropoda, Conoidea, Mitromorphidae) with the description of seven new species, Zootaxa 3931 (2), pp. 151-195 : 153

Subgenus: Mitrolumna Bucquoy, Dautzenberg & Dollfus, 1883: 121

type species: by monotypy, Mitra columbellaria Scacchi, 1836 [ Mitra olivoidea sensu Bucquoy, Dautzenberg & Dollfus, 1883 (not Cantraine), here accepted as Mitromorpha (Mitrolumna) columbellaria ( Scacchi, 1836) ].

Diagnosis. Shells of Mitromorpha (Mitrolumna) are of small size (maximum length ca. 10 mm), robust, fusiform, biconic. The sculpture consists prevalently of spiral cords, frequently vanishing on the periphery. Axial ribs present especially on the first teleconch whorls. Growth lines somehow lamellose visible over the entire surface. Anal sinus shallow. All species studied herein have a paucispiral protoconch, indicating a non-planktotrophic development, shiny and sculptured by sparse microgranules. Adults develop two columellar folds, of which the posterior is often stronger. Inner side of the outer lip with a series of denticles. Siphonal canal short and wide. Coloration varying, from monochrome, to patterned with blotches, flammulae or bands.

The radula of Mitromorpha atramentosa ( Reeve, 1849) is toxoglossate, formula 1:0:0:0:1, and the “shaftlike” teeth was compared with that of the type species M. filosa ( Orr, 1959: 77, figs 1, 2). Bouchet & Warén (1980: 7, fig. 6) figured a similar radula under the name M. olivoidea , which we argue was a specimen of Mitrolumna columbellaria , type species of Mitrolumna (see also Rolán & Boyer 2001:126, fig. 48; Mifsud 2001: Plate 1, fig. 5, same figure as Bouchet & Warén 1980).

Soft parts. Triangular shield-shaped foot, truncated anteriorly and narrow posteriorly. Small head with shortly protruding buccal mass, and eyes on lateral bulges at about mid-length of the tentacles. Siphon cleft on its lower, “held erect during motion” ( Mifsud 2001:5). Operculum absent in all species collected alive. Variable pattern of external coloration of the soft parts ( Figs 1 O; 11G; 24D).

Figures

FIGURE 1. Mitromorpha columbellaria (Scacchi, 1836). A-C. Scilla, Italy, 40 m, H = 6.75 mm (AR); D. Neotype of Mitromorpha algeriana (Pallary, 1900 ex Monterosato ms), Oran, Algeria, H = 5.75 mm (MNHN, IM- 2000 - 27714); E – F. Algeria, H = 7.25 mm (MCZR, M- 21 - 17319), labelled “ Mitromorpha algeriana v. cingulosa ” (Monterosato in schedis); G – I. Neotype of Mitra. columbellaria Scacchi, Capri Is., Italy, H = 6.95 mm (MCZR, M- 21 - 17319); J – K. Holotype of Mitromorpha mediterranea Mifsud, 2001, ‘ Méditerranée’, H = 5.4 mm, (IRSN-IG 3354); L – N. Lectotype of Mitromorpha leontocroma (Brusina, 1866), H = 6.9 mm (CNHM- 2088 c); O – P. Messina, Italy, harbour 30 – 50 m, juvenile with sketch of the living animal (by Danilo Scuderi).