Margarella expansa (Sowerby, 1838)

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 : 47

Margarella expansa (Sowerby, 1838)

Fig. 2F

Margarita expansa Sowerby, 1838a: 24 ; Sowerby, 1838b: pl. 134, figs. 16, 17

Photinula expansa — Melvill & Standen, 1907: 126; Melvill & Standen, 1912: 121

Margarella expansa — Zelaya, 2004: figs. 2, 4, 7, 16–18, 21, 22 (protoconch and radula)

Examined material. 3 an. and 9 sh. (MACN-In 40666).

Description. Shell width to 8.5 mm (up to 14.1 mm according to Strebel 1905a); trochiform, solid. Protoconch of about 1 convex whorl; transition to teleoconch poorly defined. Teleoconch of up to 4.5 whorls, slightly convex in outline; the latter widely laterally expanded, comprising about 85% of total shell height. Suture impressed. Surface white, shiny, iridescent green; only sculptured with faint growth lines. Aperture rounded, interior iridescent; columellar callus thick, expanded, forming a depression over the umbilical area. Operculum rounded, multispiral; pale brown, translucent.

Figures

FIGURE 2. A. Parmaphorella melvilli (Thiele, 1912), MACN-In 40660, scale bar = 4 mm. B. Puncturella conica (d´Orbigny, 1841), MACN-In 40661, scale bar = 2 mm. C. Anatoma conica (d´Orbigny, 1841), MACN-In 40662, scale bar = 1 mm. D. Scissurella clathrata Strebel, 1908, MACN-In 40663, scale bar = 0.5 mm. E. Calliostoma cf. moebiusi Strebel, 1905, MACN- In 40665, scale bar = 4 mm. F. Margarella expansa (Sowerby, 1838), MACN-In 40666, scale bar = 2 mm. G. Ganesa sp., MACN-In 40667, scale bar = 1 mm. H. Liotella crassicostata (Strebel, 1908), MACN-In 40664, scale bar = 0.25 mm. I. Colpospirella algida (Melvill & Standen, 1912), MACN-In 40668, scale bar = 2 mm. J. “Cirsotrema” strebeli Zelaya & Güller, 2017, MACN-In 40673, scale bar = 2 mm. K. Cerithiopsis (?) caelatum (Gould, 1849), MACN-In 40677, scale bar = 2 mm. L. Cerithiopsilla burdwoodiana (Melvill & Standen, 1912), MACN-In 40674, scale bar = 1 mm. M. Cerithiopsilla sp., MACN-In 40675, scale bar = 1 mm. N. Eumetula michaelseni (Strebel, 1905), MACN-In 40676, scale bar = 1 mm.