Caecum s.l. Fleming, 1813
Caecum Fleming, 1813: 67 . Type species (SD: Gray, 1847) Dentalium trachea Montagu, 1803, Northeastern Atlantic.
Odontidium Philippi, 1836: 102 . Type species (OD) Odontidium rugulosum Philippi, 1836, Magnisi, Siracuse, Sicily.
Brochina Gray, 1857: 101 . Type species (OD) Dentalium glabrum Montagu, 1803, European Atlantic.
Elephantanellum Bartsch, 1920: 567 . Type species (OD) Caecum heptagonum Carpenter, 1857 . Mazatlan.
Micranellum Bartsch, 1920: 568 . Type species (OD) Caecum crebricinctum Carpenter, 1864 . San Diego, California.
Caecum (Defolinia) Weisbord, 1962: 166 . Type species (OD) Caecum (Defolinia) tomaculum Weisbord, 1962, Mare formation, Punta Gorda, Venezuela †.
Pictocaecum Habe, 1978: 3 . Type species (OD) Pictocaecum japonicum Habe, 1978, Kyushu, Japan.
Diagnosis. Shell minute; teleoconch tubular, slightly curved, smooth or crossed by axial ribs, longitudinal grooves, lines, cords, or a combination. Posterior end closed by conical septum. Protoconch planispirally coiled.