Sinezona Finlay 1926

“Sinezona n. gen.

I propose this name for the Schismope brevis group, naming that species as type. The distribution of species in this group invites consideration, Hedley's brevis being recorded from Lyall Bay (type), Snares Island, in 50 fathoms, and Lyttelton Harbour; while the subspecies laevigata Iredale is given as from Sandfly Bay (type) and Lyall Bay. Examination of numerous specimens shows that there is but one species of Sinezona at Lyall Bay, differing from all the southern forms in its more central apex and inflated spire-whorls. Laevigata Iredale should be regarded as a distinct form, characterized by low and generally quite smooth spire, lateral elongation of the last whorl, less tumid whorls (noticeable especially on the base), and short fasciole. I have recorded it from Taieri Beach (Trans. N.Z. Inst., vol. 55, p. 517, 1924), and it seems to be typically a Forsterian form, but Snares specimens are not at present separable; brevis, of course, does not occur at the Snares. Finally, Schismope subantarctica Hedley (Rep. Austr. Antarct. Exped., vol 4, pt. 1, p. 36, pl. 5, figs. 54, 55, 1916), from Macquarie Island, must be added to the Neozelanic list of Sinezona. Miss Mestayer (Trans. N.Z. Inst., vol. 51, p. 130, 1919) has recorded this species from Lyall Bay and the Snares, but these records may be rejected without much hesitation; subantarctica is easily distinguished from the Lyall Bay brevis, while it differs from laevigata in being smoother, less elongate laterally, the last whorl rapidly descending downwards, and in having—in the unique type—no fasciole behind the perforation. The nearest approach to subantarctica I have seen is an undescribed species from the Chatham Islands. The absence of the fasciole-girdle suggests the name chosen for the genus and will afford a ready means of recognition; the whole facies, however, is peculiar. S. lacuniformis Watson (Chall. Rep., vol. 15, p. 118, pl. 8, fig. 8), from off the West Indies is superficially like this group, but has a gaping umbilicus; in Sinezona this is generally sealed up by the inner lip.”

(Finlay, 1927: 341)

Ariella is a genus of minute sea snails, marine gastropod mollusks or micromollusks in the family Scissurellidae, the little slit snails.

Sinezona é um gênero de gastrópodes pertencente a família Scissurellidae.