festiva Ninomiya, 1991
Description: Shell broad, aperture length about two-thirds of total shell length.
Spire calloused, callus terminating in front of the aperture;
suture covered by callus. Spire
whorls smooth or microscopically spirally ribbed, ribs ending at
aperture. Body whorl with
calloused subsutural band, edged by a weak groove below.
Non-calloused part of body whorl with microscopic axial and
spiral striae. Columella
smooth, without plaits; fasciolar band with weak central ridge, upper
and lower halves flat and smooth; ancillid band defined by ancillid
groove or by colouration, ancillid groove weak or absent.
Non-calloused areas of body whorl salmon with axial zigzag brown
lines, and a spiral band of brown flames above the ancillid band; subsutural
band with brown streaks or rectangular patches; fasciolar
band fawn, pillar area white. Operculum unknown.
Up to 25 mm in length.
Distribution: Known from
Taken in 27-210 metres. Uncommon.
This species is distinguished by having no plaits on the
columella. It is very
similar to large specimens of A.
oblonga, but that always has ribs on the columella, even if weak.
This species may be a deep water form of A.
oblonga; it is very similar in colour pattern, and differs from
large specimens of A. oblonga
only by the smooth columella. However,
there is overlap in latitudinal range and depth range of the two.
Pending further research, it is retained as a separate species.
Copyright Des Beechey 2004