The Family Seguenziidae Verrill, 1884 in the Northeast Pacific, including a comment on excessive numbers of taxonomic data portals Author Geiger, Daniel L. text Zoosymposia 2019 2019-02-19 13 61 69 journal article http://dx.doi.org/10.11646/zoosymposia.13.1.7 c6aa05ac-8e39-4b3f-bfe1-b0e6b1a7ecf9 1178-9905 3558484 urn:lsid:zoobank.org:pub:16D27C71-5A6C-4ADF-AD6C-6B07C2773112 Seguenzia Jeffreys, 1876 ( Figure 2 ) Seguenzia Jeffreys, 1876: 200 . Type species (M): S . formosa Jeffreys, 1876 . Northwest Atlantic. Description. Shell to 10 mm , thin, fragile, umbilicate or anomphalous, external and internal surfaces with nacreous luster. Apertural lip bordering three labral sinuses often flaring in mature shells. Columella curved, ending abruptly. Sculpture of narrow spiral carinae, basal cords; fine spiral threads, sharp axial riblets curving parallel to labral sinuses. Remarks. Species occur throughout the world on the lower continental slope and abyssal plain. Seguenzia occidentalis Dall, 1908 (see Keen 1971 ) is known from the Panamic Province. There are two groups of Seguenzia , 1) specimens with globular shells and with less prominent spiral keels: S. cervola , S. macleani , and 2) biconical shells with more prominent spiral keels: S. giovia , S. stephanica .