Conus (Plicaustraconus) angasi  Tryon, 1884

Common Name

"Angas's Cone"

Status

Regarded as a valid species.

Type Locality

Port Jackson, Australia

Distribution

New South Wales and Queensland, Australia, possibly restricted to the area between Sydney and Fraser Id.

Maximum Reported Size

35 mm

Description

Moderately small to medium-sized, moderately light to moderately solid; form advertex (Pl. 60, Figs. 19, 20) of smaller maximum size than typical form (Pl. 60, Figs. 16-18). Last whorl conical or ventricosely conical to broadly conical or broadly and ventricosely conical, form advertex often broader than typical form; outline convex at adapical third, straight below. Basal part of columella with a strong dentiform plait at its posterior end. Shoulder angulate, subangulate in large specimens. Spire low and usually with concave outline in form advertex, of low to moderate height and usually with slightly sigmoid outline in typical form. Larval shell of 1.75-2 whorls, maximum diameter 1.1-1.3 mm. Teleoconch sutural ramps almost flat, with 1-2 increasing to 4-8 spiral grooves, with additional spiral striae in latest whorls. Last whorl with rather closely spaced spiral ribs at base.

Ground colour white to pale pink. Last whorl with pinkish to light brown spiral bands below shoulder, above centre and within basal third. Spiral rows of brown dots, dashes, spots and bars extending from base to shoulder, usually concentrated and partially fused near and within the spiral colour bands. Larval whorls white. Postnuclear sutural ramps with brown radial streaks usually extending beyond outer margins. Aperture white, tinged with cream and pink deep within.

Shell Morphometry

L 30-46 mm
(form advertex 27 - 37 mm)
RW 0.08-0.20 g/mm (L 27-46 mm)
(L 27-46 mm)
RD 0.65-0.71
(form advertex 0.66 - 0.75)
PMD 0.77-0.89
(form advertex 0.81 - 0.90)
RSH 0.08-0.19
(form advertex 0.01 - 0.09)

Habitat & Habits

In 50-250 m. Form advertex is reported from sand bottom and seems to have a more limited bathymetric range (120-200 m).

Discussion

C. angasi is similar to C. baeriem> and C. wallangra; for comparison, see the Discussions of the latter species. The conchological differences between C. angasi and C. advertex do not justify separation at the species level. Because they occur sympatrically, C. advertex should be provisionally considered a form of C. angasi (see Walls, [1979]; Coomans et al., 1979b; Richard, 1990).

Related Taxon

References

Geographic Distribution


Image courtesy of A.J. Kohn