Type species:Saturnalis circularis  Haeckel (SD [Campbell, 1954, p.D54])
Description:1b. Tribus: Xiphostylida. Monosphaeria dissacantha (aculeis duobus oppositis, in uno axi sitis).
B. aculeis apice annulo siliceo conjunctis.
BI. annulo laevi.
[1b. Tribe: Xiphostylida. Monosphaeria with two spines (two opposite spines, situated in one axis).
B. With the apices of the spines joined by a siliceous ring.
BI. With the ring smooth.]
Stratigraphic range:[No information given]
Etymology:[No information given]
Subsequent descriptions:YES

Description and dimensions:Pores of the spherical shell regular, circular, hexagonally framed, twice as broad as the bars. Ten to twelve pores on the half equator. Ring circular, smooth, its diameter three times as great as that of the sphere.
      Diameter of the sphere 70µm, pores 5µm, bars 25µm; diameter of the circular ring 200µm, thickness of the axial beams and the ring 10µm.
Repository:[No information given]
Type locality:South Atlantic, west of Tristan da Cunha, Challenger Station 332, 37°29'S-27°31'W, 2200 fms. Globigerina ooze with numerous Radiolaria.
Original stratigraphic range:[No information given]
Etymology:[No information given]
Subsequent descriptions:YES

Literature cited:- Campbell, A. S. (1954). Radiolaria. Treatise on Invertebrate Paleontology. R. C. Moore. Lawrence, Kansas, USA, Geological Society of America and University of Kansas Press. Part. D, Protista 3: 11-195.
- Haeckel, E. (1881a). Entwurf eines Radiolarien-Systems auf Grund von Studien der Challenger-Radiolarien (Basis for a radiolarian classification from the study of Radiolaria of the Challenger collection). Jenaische Zeitschrift für Naturwissenschaft, 15:418-472.
- Haeckel, E. (1887a). Report on the Radiolaria collected by H.M.S. Challenger during the years 1873-1876. Report on the Scientific Results of the Voyage of the H.M.S. Challenger, Zoology, 18, clxxxviii + 1803.