Vaginulina soluta var. carinata – Silvestri, A. 1898. Foraminiferi Pliocenici della Provincia di Siena. Parte II. Memorie dell'Accademia Pontificia dei Nuovi Lincei, Roma. 15: 155-381.page(s): p. 166 pl. 2 fig. 8.
Vaginulinopsis carinata (Silvestri, 1898) – Loeblich and Tappan 1987 (1988), Foraminiferal genera and their classification. p. 412, pl. 450, figs. 1-6.
Vaginulina costata (not Batsch 1791) — Goës, A. 1894, A synopsis of the Arctic and Scandinavian Recent Marine Foraminifera hitherto discovered. Kongl. Svenska Vetenskaps-Akademiens handlinger, 25, no.9: p. 67, plate 12, figs. 666 & 666a.
Description: Test elongate, slightly arcuate, apical end rounded, laterally compressed, with a distinct keel, then more ovate in cross section. Chamber arrangement initially spiral then rectilinear; the initial spire in microspheres comprises about 1 to 1,5 windig of 10-15 chambers, whereas in megalospheres the spire is reduced to less than one winding, sometimes comprising only the first two or three chambers. Latest chambers slightly inflated, often ovate in cross section; chamber width over twice the chamber height; number of chambers up to 20, often about 15 in fully grown specimens. Aperture radiate, eccentric, and protruding. The apical keel continues dorsally along the test lenght; lateral and ventral surface is covered with costae, which run obliquely along axis of the test and fuse with the dorsal keel. The apertural face is smooth and commonly also the last two or three chambers are smooth or only faintly costated; sutures vary for being horizontal to slightly oblique. Length of the largest is 8 mm, but most are around 5 mm. About 450 specimens were picked from 61 of the 1031 Bioice samples that were checked for forams.
Diagnosis: Vaginulina cf. V. linearis differs from V. carinata in being more slender; chamber width is slightly less or equal to chamber height; the costae are relatively higher, lie closer together and cover the whole lenght of the test, except the apertural face.