Meteuthria martensi Strebel 1905

Meteuthria martensi (Strebel, 1905)

Figures 11 A–K, 12A–E

Euthria Glypteuthria martensi Strebel, 1905: 630, pl. 21, figs. 13, 13 a, b. Euthria Glypteuthria agnesia Strebel, 1905: 631, pl. 21, figs. 14, 14 a, b, c. Meteuthria martensi (Strebel). Thiele, 1912: 243, pl. 13, fig. 7, pl. 16, fig. 18; Powell, 1951: 149, fig. K62; Castellanos, 1992:

20, pl. 1, fig. 8 (only).

Meteuthria agnesia (Strebel). Dell, 1971: 206.

Type material. [Euthria Glypteuthria martensi] the following lots, housed at the ZMH collection should be regarded as syntypes: 1 spm., Magellan Straits, Borja Bay, SE 6201 (1167); 3 spms., Puerto Harris, 10 fms [18.3 m] depth, SE 6193; 4 spms., Ebendaher, 15 fms. [27.4 m] depth, SE 6192; 3spms., Puerto Condor, SE 6208; 1 spm., Basket Is., M 108; 2 spms., Voilier Cove, 10 fms. [18.3 m] depth, SE 6216 (661); 2 spms., Ushuaia, 5 fms., [9.1 m] depth, M124; 2spms., Ushuaia, 10 fms. [18.3 m] depth, M122; 1 spm., Ushuaia, 12–15 fms. [21.9-27.4 m] depth, SE 6220 (786); this specimen (Figs 10A–C) is here designated as lectotype in order to preserve stability of nomenclature, in agreement with ICZN article 74. [Euthria Glypteuthria agnesia] 1 spm., Picton Is., Banner Cove, 3 fms. [5.4 m] depth, M 168.

Type locality. Ushuaia, Tierra del Fuego, Argentina, here selected.

Description. Shell small, up to 12 mm in height, fusiform, of five slightly convex whorls; protoconch (Figs 11 J, K) of about 2 convex whorls, translucent with quite distinctive closely spaced axial threads overall, transition to teleoconch weakly defined; suture impressed, slightly channelled; aperture oval, labrum thick; siphonal canal rather deep, oblique and long; parietal callus thin; growth lines close spaced over the entire shell; spiral ornamentation of thick threads, 4 on the first two whorls, 5 to 6 on the others; axial sculpture of 13 to 15 varices, which develop nodes when crossing the spiral threads; periostracum translucent, yellowish to brownish; colour chalky whitish, some specimens darker.

Operculum (Fig. 11 I), pale yellowish, shape ovate-elliptical, nucleus subterminal, attachment area towards left side.

Radula (Figs 12 A–C) with rachidian teeth absent. Laterals triangular, Prosipho -like or fan shaped (basal plate with “handle”), with four major, slightly curved, cusps pointing towards the center of the ribbon, sometimes 2 to 3 very small cusps on the outer side of the teeth.

Penis large, flat, with a thick, blunt papilla rising from a cavity (Figs 12 D–E).

Material examined. Argentina: 1 shell, 35°30’S, 53°10’W, 91.5 m depth, (MACN-In 15611); 1 shell, 35°42’S, 54°40’W, 128–138 m depth, (MACN-In 15827); 1 spm., 39°S, 58°W, about 600 m depth, (MACN-In 32893); 3 shell, 4 spms., Ushuaia, (MACN-In 40519); 1 spm., 54º51.596’S, 68º31.618’W, Tierra del Fuego, 25 m depth, (MACN-In 40521); 4 spms., 55°6.26’S, 66°28.14’W, 71 m depth, (MACN-In 40520).

Chile: 1 shell, 52°41’S, 74°35’W, 188–247 m depth, (USNM 898754); 1 spm., 1 shell, Rada Picton Is., 27.5 m depth, (MACN-In 35132).

Distribution. Straits of Magellan and Beagle Canal, Tierra del Fuego in shallow waters; off Buenos Aires in more than 100 m depth.

Remarks. This uncommon species was included by Strebel in Glypteuthria because of the similarity of its shell to that of G. meridionalis. However, the radula, as stated by Thiele (1912), is different enough to justify his new genus Meteuthria. In addition, the protoconch with axial threads is also quite distinctive. One syntype of Euthria agnesia Strebel, a very damaged specimen, (illustrated in Fig. 11 D–E) was the basis on which the two species were synonymized.