SIGMOILOPSIS Finlay, 1947
Type species: Sigmoilina schlumbergeri Silvestri, 1904 (*2933), p. 267; OD.
Sigmoilopsis Finlay, 1947 (*1130), p. 270.Test ovate in outline, chambers one-half coil in length, with rapidly changing planes in the early stage resulting in two spiralling series that appear sigmoid in section, gradually becoming planispiral in the adult, chambers with floors, chamber lumen narrow; wall thick, porcelaneous but enclosing a large quantity of agglutinated quartz particles, sponge spicules, and shell fragments; aperture terminal, rounded, with a small tooth. Miocene to Holocene; Europe; Atlantic; Caribbean; Australia; New Zealand.
Remarks: As no type specimen was originally designated for Sigmoilina schlumbergeri, the specimen (BMNH) illustrated by Brady (1884, *344, pl. 8, figs. la, b) as Planispirina celata (Costa), from Porcupine Station 23, west of Ireland at 630 fathoms, was designated as the lectotype (Loeblich and Tappan, 1964, *1910, p. C466).