“Trophon minutus Strebel, 1907 (Fig. 353)
Trophon minutus (Strebel MSS) Melvill and Standen, 1907: 167, pl. 1, figs 7, 7a; Strebel, 1908: 44, pl. 4, figs 47a, b; Melvill and Standen, 1912: 354; Powell, 1951: 155; Carcelles, 1953: 188, pl. 3, fig. 54; Gaillard, 1954: 681; Powell, 1960: 154; Picken, 1979: 119 (reproduction); Oliver and Picken, 1984: 113, figs 33a, b.
Trophon condensatus Hedley, 1916b: 60, pl. 9, fig. 98; Powell, 1960: 153; Arnaud, 1972c: 131, fig. 21; Cantera and Arnaud, 1984: 63.
MATERIAL EXAMINED: Australasian Antarctic Expedition, Commonwealth Bay, Adelie Land, 46 m, holotype of T. condensatus (AM); NZOI Stn Z1807; Eltanin Stns 1002, 1003, 1581; Hero Stns 5, 447, 448; Oregon State University Stns AH4-20, AH4-30, AH4-45, AH4-50.
DISTRIBUTION: Trophon minutus can now be recorded from the Antarctic Peninsula, the South Shetlands, South Orkneys, South Sandwich Islands and South Georgia in 2-220 m, and from off the antarctic continent from between 140°E and 170°E in 30-45 m. The three specimens from NZOI Stn Z1807 are the only ones so far collected from the Ross Sea. Cantera and Arnaud recorded it from off Kerguelen Island (24-138 m).
REMARKS: Comparison of the holotype of Trophon condensatus Hedley with a series of T. minutus from the islands of the Scotia Arc shows that the two are conspecific. Hedley distinguished condensatus from minutus by the more closely spaced axial lamellae. Arnaud (1972c) noted the same character but considered that condensatus might prove to be a subspecies of minutus. The holotype of condensatus has 30 axial lamellae on the last whorl. Melvill and Standen (1907) stated that minutus had 22 axial lamellae. A sample of seven species from the Antarctic Peninsula, the South Orkneys and the South Sandwich Islands showed a range of 24-32 lamellae on the last whorl (mean 27), so this distinction cannot be maintained. In all other characters the two forms seem identical. The number of lamellae is variable within wide limits in other antarctic species of Trophon, and this seems true for minutus also.
The apex in minutus is damaged on many specimens, and the resultant cavity filled in with secondary callus. In some cases the damage has occurred below the protoconch, which may then be cemented on excentrically when the animal repairs the shell.”
(Dell, 1990: 203-205)
