Seguenziidae Verrill, 1884

Geiger, Daniel L., 2019, The Family Seguenziidae Verrill, 1884 in the Northeast Pacific, including a comment on excessive numbers of taxonomic data portals, Zoosymposia 13, pp. 61-69 : 62

Seguenziidae Verrill, 1884

( Figures 1–3 )

Description. Shell trochiform, turbiniform, or planispiral, 2–10 mm, umbilicus narrow or anomphalous, interior nacreous except Adeuomphalus . Peritreme incomplete (entire in Adeuomphalus ), aperture lacking a slit or foramen, but some genera with up to three labral sinuses. Operculum corneous, paucispiral.

Remarks. In the northeast Pacific, all sequenziid species occur on outer continental shelves at deep to abyssal depths, where they are detritivores ( Quinn, 1983b). Specimens are seldom collected and the family is poorly known.

Figures

FIGURE 1. A–B. Carenzia golikovi Geiger, 2017. A. 5180 m, Abyssal plain W of Oregon, S of Gulf of Alaska, Alaska (approximately 45° N, 153.8° W) (LACM 3317, holotype), 5.3 mm. B. 5100 m, Aleutian Trench, Alaska [near western end of chain], (52° 12'N, 175° 44'E) (LACM 3318, paratype). C. Carenzia inermis Quinn, 1983. 2820 m, Cascadia Abyssal Plain, off Oregon (LACM 1806, holotype), 6.8 mm. D. Asthelys careyi Geiger, 2017. 5180 m, abyssal plain W of Oregon, S of Gulf of Alaska, Alaska (approximately 45° N, 153.8' W) (LACM 3320, holotype), 7.0 mm. E–F. Oligomeria conoidea Galkin & Golikov, 1985. E. 166 m, S of Attu Island, Aleutian Islands, Alaska (LACM 1997-163.7), 5.9 mm. F. 219 m, NE of Semisopochnoi Island, Aleutian Islands, Alaska (LACM Station 86-330), 4.7 mm.

FIGURE 2. A–B. Seguenzia cervola Dall, 1919. A. 1130–1266 m, off North Coronado Island, Baja California (USNM 209229, holotype), 4.5 mm. B. 3592–3798 m, SW of Farallon Islands and W of Pioneer Seamount, off San Francisco County, California (USNM 701260, holotype of S. megaloconcha), 9.2 mm. C–D. Seguenzia macleani Geiger, 2017. C. 5100 m, Aleutian Trench at 175° 44' E (LACM 3321), holotype, 8.7 mm. D. 5180 m, abyssal plain W of Oregon, S of Gulf of Alaska (approximately 45° N, 153.8° W) (LACM 3486, paratype), 9.6 mm. E–F. Seguenzia giovia Dall, 1919. E. 874–1097 m, off Santa Catalina Island, Los Angeles County, California (USNM 209228, holotype), 6 mm. F. 3900 m, Tufts Abyssal Plain, W of Lincoln County, Oregon (LACM 2065, holotype of S. quinni), 7.6 mm. G–H. Seguenzia stephanica Dall, 1908. G. 2816 m, Cascadia Abyssal Plain, off Oregon (LACM 70-140.5), 7.1 mm. H. 5100 m, Aleutian Trench, Alaska at 44° N, 175° E (LACM), 5.2 mm.

FIGURE 3. Adeuomphalus trochanter Warén & Bouchet, 2001. 2068 m, Juan de Fuca Ridge, off Oregon (MNHN 21051, holotype), 2.7 mm [SEM by Anders Warén].