Mauroceras kajiyamai ( Habe, 1963 )

Vannozzi, Angelo, 2023, The Caecidae from BIOMAGLO Expedition in the Mayotte-Glorieuses area (Mollusca, Gastropoda), Zoosystema 45 (12), pp. 421-434 : 431

Mauroceras kajiyamai ( Habe, 1963)

( Fig. 3M )

Meioceras kajiyamai Habe, 1963: 231 , fig. 5. — Vannozzi 2019a: 91 (and synonymy therein).

† Parastrophia christinae Selli, 1974: 305 , pl. 16, figs 5, 6.

† Meioceras mateldae Selli, 1974: 306 , pl. 16, figs 8, 9.

TYPE MATERIAL. — Holotype. Japan • dd; Amami-Oshima , Ankyaba, Kakeroma Jima; NMNS figured by Pizzini et al. (2013: fig. 15 M).

TYPE LOCALITY. — Pacific Ocean, Japan, Amami-Oshima, Ankyaba, Kakeroma Jima.

MATERIAL EXAMINED. — Mayotte • 1 dd; Mozambique Channel , W Mayotte, BIOMAGLO Stn DW4847; 12°41’S, 44°57’E; 738- 763 m depth; 30.I.2017; MNHN .

DISTRIBUTION. — Indo-West Pacific, from the eastern coast of Africa to Maldives, Papua New Guinea, Philippines, Japan, New Caledonia ( Habe 1963; Hasegawa 2000; Pizzini et al. 2013; Vannozzi 2017; 2019a; 2019b; unpublished data).

DIAGNOSIS. — Shell of average size for the genus, semitransparent whitish, glossy. Tube subcylindrical, tapering toward both the apex and the aperture. Maximum width located at about one quarter of the length close to the aperture. Sculpture of fine, regular rings. Septum on the cutting plane, with a strong mucro, showing a straight dorsal side and a sloping, slightly convex ventral side. Young stage showing a rapid growth and a cow-horn shape. Protoconch planispiral of about 1.75 whorls with a shallow sinusigera. Adult shell length 2.8 mm.

REMARKS

A single, slightly worn specimen was found in the studied material. No differences can be seen with respect to specimens coming from other Indo-West Pacific localities.

Figures

FIG. 3. — Side and ventral views of Caecum Fleming, 1813 and Mauroceras Vannozzi, 2019 species from BIOMAGLO expedition.: A, C. hyalinum Vannozzi, 2022 from Stn DW4847; B, C. egenum Vannozzi, 2017 from Stn DW4854; C, C. cf. mauritianum de Folin, 1868 from Stn DW4820; D, E, C. mauritianum; D, holotype MNHN-IM-2000-24911; E, paratype MNHN-IM-2000-24912; F-L, C. cooki Pizzini & Raines, 2011; F, specimen from Stn DW4847; G, H, specimens from Stn DW4854 (H, juv.); I-L, specimens from Stn DW4820; M, M. kajiyamai (Habe, 1963) from Stn DW4847; N, M. sandwichense (de Folin, 1881) juv.from Stn DW4854. Scale bar: 1 mm. Images D, E, courtesy of Ph. Maestrati (MNHN).