Material Examined. California: Santa Maria Basin, Phase I, sta. 40, 392 m (1); Phase II, sta. R-2, 161 m (1); sta. R-6,410 m (1). Other material: 247 lots in LACM collection.
Description. Axial ribs strong to weak, retractive, extending suture to suture; 3 major spiral cords per whorl, incremental cords added in final whorl. Intersections of cords producing large beads that may project with high relief; whorl sides rounded. Height 7-11 mm.

Type Locality and Type Specimens. Middle Pleistocene, Santa Barbara Formation, Santa Barbara, California. Holotype: USNM 7154. Bittium subplanatum: Santa Catalina Island, California; holotype: USNM 160076. Alabina calena: San Luis Obispo Bay, 252 fathoms; holotype: USNM 271070.
Distribution. Off Point Pinos, Monterey County, California (37°N), to Islas San Benito, Baja California (28°N).
Habitat Common on soft bottoms, 30-500 m.

Remarks. Shells vary in the number of axial ribs per whorl and relative strength of the axial ribs. Carpenter's name was based on Pleistocene material from Santa Barbara. Hertz (1981) illustrated additional fossil specimens. The synonym "Alabina" calena represents a form occurring at depths of 200-300 m, in which axial sculpture is not developed on the mature whorls.