Seguenzia stephanica Dall, 1908

(Figure 2 G–H)

Seguenzia stephanica Dall, 1908: 325 . Holotype USNM 123034. Ventana Bay, Baja California, 1820 m.

Seguenzia caliana Dall, 1919: 344 . Holotype USNM 207674. Off San Diego, California, 417 fms [= 762 m]. New synonym.

Seguenzia certoma Dall, 1919: 343 . Holotype USNM 211167. Off Point Loma, San Diego, California, 565–680 fms [= 1033– 1243 m]. New synonym.

Description. Shell to 8 mm, globular biconical; carinated spiral cords below suture, strongest one mid shoulder, approximately 8–15 from periphery to umbilicus, count increasing with size; intercalated spiral lines at best faint; axial cordlets distinct. Umbilicus very narrow in small specimens, closed by callus in larger shells. Columellar wall thickened, terminating in sharp spur. Flaring of lip variable depending on size, preservation of specimen.

Distribution. Aleutian Islands, Alaska (175°E) to Peru (3° S). 750–5100 m.

Remarks. Smaller specimens have proportionally more pronounced spiral and axial sculpture. The types of the three nominate taxa represent growth stages of the same species.