Seguenzia formosa Jeffreys 1876

• Main Authors: Salvador, Rodrigo B., Cavallari, Daniel C., Simone, Luiz R. L.
• Format: Other/Unknown Material
• Language: unknown
• Published: Zenodo 2014
• Subjects: Biodiversity; Taxonomy; Animalia; Mollusca; Gastropoda; Seguenziida; Seguenziidae; Seguenzia; Seguenzia formosa; North Atlantic
• Online Access: https://doi.org/10.5281/zenodo.6138472; http://treatment.plazi.org/id/7B1480144B47FF9DFF7AFE64D3CFC093

Seguenzia formosa Jeffreys, 1876 (Figs. 22–24) Seguenzia formosa Jeffreys, 1876: 200; Jeffreys, 1885: 42; Quinn, 1983b: 728 (figs. 6, 17, 23). Seguenzia lineata: Rios, 2009: 72 (textfig.). Seguenzia monocingulata : Marshall, 1983: 236; Rios, 1985: 33 (pl. 14, fig. 141); Gofas et al ., 2001: 184. Seguenzia hapala : Rios, 1985: 33 (pl. 14, fig. 140); Rios, 1994: 44 (pl. 14, fig. 151); Rios, 2009: 72 (textfig.); Benkendorfer & Soares-Gomes, 2009: 151. Type locality: Valorous Expedition, North Atlantic, 1450 fathoms (ca. 2650 m depth) (Jeffreys 1876). Distribution: Morocco, Cape Verde, off USA to Brazil, ca. 80–3700 m depth (Jeffreys 1885; Rosenberg et al . 2009). In Brazilian waters: off Pernambuco state, ca. 640–1235 m depth (Watson 1879); off Cabo de Santa Marta, Santa Catarina state, and off Tramandaí, Solidão and Bojuru, Rio Grande do Sul state (Rios 2009). New occurrence: Southeastern Brazil, from Espírito Santo to Rio de Janeiro, 295–3450 m depth. Description: Shell small, conical, relatively thick-walled, with stepped spire. Color nacreous glossy white. Protoconch (~1 whorl) prominent, bulbous, microporous. Teleoconch sculpture (except whorl base) consisting of very strong spiral cords (only a single one visible on early whorls), with widely spaced axial threads and very fine spiral threads between spiral cords and suture; spire whorls bearing two visible spiral cords: a weaker subsutural one, and a stronger supramedian that produces a distinct keel; axial threads prosocline above median keel and opisthocline below it, creating a continuous sigmoid pattern. Whorl base sculptured by 6–8 spiral cords; axial threads between cords. Whorls strongly concave between cords and suture, with overall angular shell profile. Suture obscured by subsutural carina. Aperture quadrangular, with a strong columellar tooth and three labral sinuses: a deep subsutural sinus; a shallow sinus in peripheral part of basal region of aperture; and a very shallow sinus in palatal region of aperture, corresponding to the carina. ...