Argeneuthria philippii (Strebel, 1905) new comb.

Figures 23 A–M, 24A–B

Euthria philippii Strebel, 1905: 626, pl. 21, figs. 16, 16a–c.

Type material. 4 syntypes: 1 shell, Cape Valentin (Strait of Magellan), 150 fms. [274.3 m] depth, (ZMH 3123) (ex SE 6210, Number 1 from Strebel, 1905: 627); 1 spm., Puerto Espinal, 8 fms. [14.6 m] depth, (ZMH 3124) (ex SE 2228 (108), Number 2 from Strebel, 1905: 626); 1 spm., 1 shell, Picton Island, Banner Cove, on roots of kelp, 3 fms. [5.4 m] depth, (ZMH 3125) (ex M168, Number 3 from Strebel, 1905: 627), one of them is here designated as lectotype in order to preserve stability of nomenclature, in agreement with ICZN article 74 (illustrated here in fig. 23A–C).

Type locality. Here restricted to Picton Is., Beagle Channel, Chile.

Description. Shell small, about 12 mm in height, fusiform, whitish, chalky, outside and inside, of six slightly convex, distinct whorls; protoconch (Figs 23 J–L), rectangular in profile, of 2 1/2 flat whorls, translucent, smooth, transition to teleoconch faded; suture almost canaliculated (grooved); aperture elliptical, siphonal canal wide and short; parietal callus very thin; spiral ornamentation of 5 thin cords, faint in the first whorl and then crossing axial varices; axial sculpture of 14 to 18 varices, usually flat when crossing the spiral cords; sometimes cords are faint, almost lost in the last whorl, so varices appear complete; sometimes the base of the last whorl only with about 10 cords; with yellowish periostracum.

Operculum (Fig. 23 M) thick, suboval, nucleus subterminal, attachment area shallow.

Radula (Fig. 24 A, B) as in A. paessleri however, the central rachidian cusp appears to be larger and thicker than the lateral cusps and the “handle” of lateral teeth is somewhat shorter and slightly sinuous. The external cusp of lateral teeth is bifid.

Material examined. Argentina: 1 spm., 35°30’S, 52°50’W, 134 m depth, (MACN-In 16636); 4 spms., 47°43’45.6”S, 65°50’15.7”W – 47°44’8”S, 65°49’39”W, 15 m depth, (MACN-In 40503); 2 shells, 51°46’S, 68°45’W, 22 m depth, (MACN-In 23864); 3 spms., Cabo Blanco, Santa Cruz, (MACN-In 17843); 1 shell, Becasses Is., Beagle Canal, Tierra del Fuego, (MACN-In 35225); 1 shell, 53°51’S, 71°36’W, 256–269 m depth, (USNM 887709); 1 shell, 53°40’S, 66°20’W, 81 m depth, (USNM 870474); 2 shells, 53°41’S, 70°24’W, 91–110 m depth, (USNM 898303); 1 shell, 53°56’S, 71°15’W, 256–320 m depth, (USNM 870465); 1 spm., 53°59’04.3”S, 67°22’59.1”W, Estancia Viamonte, live collected during low tide, (MACN-In 40504); 3 shells, 54°17.647”S, 66°15.376”W to 54°17.346”S, 66°15.531”W, 56 m depth, with bottom trawl, (MACN-In 40505); 2 shells, 54°29.52”S, 65°3.16”W, 133 m depth, (MACN-In 40506).

Chile: 1 shell, Punta Arenas, (MACN-In 8648-6b); 1 spm., Picton Is., 50–75 m depth, (MACN-In 23995).

Distribution. South of Santa Cruz province, Tierra del Fuego and the Straits of Magellan.

Remarks. Only a dozen specimens were available of this apparently variable species. The spiral ornamentation may be less developed in some specimens, showing the axial varices only. The radula shows minor differences with the other species of the genus.