Seguenzia giovia Dall, 1919

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 : 66

Seguenzia giovia Dall, 1919

( Figure 2 E–F)

Seguenzia giovia Dall, 1919: 343–344 . Holotype USNM 209228 . Off Santa Catalina Island , California Channel Islands, 190– 216 m [see remarks below].

Seguenzia quinni McLean, 1985: 337 , fig. 2. Holotype LACM 2065 . Tufts Abyssal Plain, W of Lincoln County, Oregon, 3900 m. New synonym.

Description. Shell to 7.5 mm, globular biconical; carinated spiral cords below suture, strongest on mid shoulder, from periphery to base approximately 10 of decreasing strength; fine spiral lines between cords; axial cordlets distinct; Umbilicus moderately wide, bordered by spiral carina, with funiculus; Columellar wall thickened, terminating as sharp spur. Flaring of lip variable depending on size, preservation of specimen.

Distribution. Off Oregon (45˚N) to Southern California (33˚N). 800–3900 m.

Remarks. Seguenzia quinni is a larger, better-preserved specimen of S. giovia ; note the identical teleoconch sculpture and umbilical details. The type locality of S. giovia (Albatross 4408) is most likely erroneous because it is too shallow for seguenziids, and may be any of the Albatross 4400–4407 stations at depths of 450–650 fathoms (820–1190 m), all off Santa Catalina Island, Los Angeles County, California.

Figures

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.