Thesbia michaelseni (Strebel, 1905)

Luca, Javier Di & Zelaya, Diego G., 2019, Gastropods from the Burdwood Bank (southwestern Atlantic): an overview of species diversity, Zootaxa 4544 (1), pp. 41-78 : 61

Thesbia michaelseni (Strebel, 1905)

Fig. 4K

Daphnella (Thesbia) michaelseni Strebel, 1905b: 590 , pl. 22, figs. 20, 20a–c

Thesbia michaelseni — Castellanos & Landoni, 1993: 15

Examined material. 1 an. and 2 sh. (MACN-In 40695); 1 syntype (ZMH unnumbered).

Description. Shell height to 4.6 mm (up to 10.2 mm according to Strebel 1905b); fusiform, delicate. Protoconch large, translucent, of about 1.75 slightly convex whorls; transition to teleoconch poorly defined. Teleoconch of up to 3 whorls, slightly convex in outline; last whorl comprising about 80% of total shell height. Suture impressed. Surface whitish, somewhat translucent; sculptured with very weak spiral threads, 9 to 12 on the spire whorls, and about 30 on the last whorl; well-marked growth lines are evident along all teleoconch whorls. Aperture ovate, interior white; columellar callus narrow, slightly expanded on the base; siphonal canal short, somewhat oblique, wide.

Figures

FIGURE 4: A. Proneptunea (?) minuta Castellanos, 1992, MACN-In 40694, scale bar = 1 mm. B. “Savatieria” meridionalis (Smith, 1881), MACN-In 40685, scale bar = 1 mm. C. “Savatieria” chordata Castellanos, Rolán & Bartolotta, 1987, MACN-In 40687, scale bar = 1 mm. D. Buccinidae sp., MACN-In 40686, scale bar = 1 mm. E. Fuegotrophon pallidus (Broderip, 1832), MACN-In 40690, scale bar = 5 mm. F. Trophon ohlini Strebel, 1904, MACN-In 40689, scale bar = 5 mm. G. Trophon plicatus (Lightfoot, 1786), MACN-In 40688, scale bar = 2 mm. H. Paradmete crymochara (Rochebrune & Mabille, 1885), MACN-In 40691, scale bar = 5 mm. I. Mangelia michaelseni (Strebel, 1905), MACN-In 40693, scale bar = 1 mm. J. Leucosyrinx angusteplicata (Strebel, 1905), MACN-In 40692, scale bar = 4 mm. K. Thesbia michaelseni (Strebel, 1905), MACN-In 40695, scale bar = 1 mm. L. Admete magellanica (Strebel, 1905), MACN-In 40696, scale bar = 3 mm.