“Subgenus Kerguelenatica n.subg.
Type: Natica grisea Martens, 1878
At least subgeneric status is warranted for grisea, for it has an operculum which is formed of both horny and calcareous materials. It is admirably described by Watson (1886, p. 432) as follows: `It has a thinnish calcareous layer over a pretty strong horny interior, which projects uncovered round the entire edge, but this uncovered edge is narrowest on the inner side, i.e. near the pillar of the shell or spire of the operculum. Here the exterior flat surface of the calcareous layer is thickened by a thin, dirty grey, spreadout spot of limy substance. Beyond this spot the surface of the calcareous layer is strongly scored with radiating lines. Its inner surface can be seen through the horny layer to be sharply and delicately striate spirally.' Like the Amauropsis series the shell lacks a funicular callus and has a thick yellowish brown epidermis.
As already explained under Amauropsis, the species grisea cannot be covered by Friginatica as Hedley intended, for the south-eastern Australian genotype, beddomei, apparently lacks epidermis, and according to Cotton (1931, p. 20) the operculum is horny.
Unfortunately, in describing the Macquarie Island Friginatica pisum Hedley (1916) made no reference to the operculum, but Tomlin (1948), p. 228, remarked that it is dark coloured and horny.' The species may be located provisionally in Amauropsis. I favour reinstating Marwick's Sulconacca (1924, p. 556), type : S. vaughani Marwick, Lower Miocene, New Zealand, in preference to Friginatica which becomes restricted to its Recent south-eastern Australian genotype. Sulconacca has the umbilical area margined by a strong spiral ridge.
The presumed occurrence of Amauropsis in both the Arctic and Antarctic regions may seem unnatural and certainly brings up once more the question bipolarity.
Amauropsis is a high-latitude stenothermic mollusc related to Polinices, which is widely distributed in warmer seas. Polinices is of considerable antiquity (common in the Tertiary of most regions), and it is likely that Amauropsis also had sufficient time and opportunity during the colder periods of the Pleistocene to accomplish bipolar distribution. The new subgenus Kerguelenatica is considered to be a local product from Amauropsis originating in the Kerguelenian Province. From consideration of time Sulconacca is probably not related nor is Friginatica in its restricted usage.”
(Powell, 1951: 117)
Kerguelenatica is a genus of predatory sea snails, marine gastropod mollusks in the family Naticidae, the moon snails.[1]
Species within the genus Kerguelenatica include:
Kerguelenatica is a genus of predatory sea snails, marine gastropod mollusks in the family Naticidae, the moon snails.
