Emended description:Sethoperinae, the basis of the skeleton which is formed by spines A, D, Lr and Ll which are almost equal in length and extend from a very short MB. Since MB is short, it seems as if the spines extend from one point, constituting angles of 120°, and that there is a triradiate symmetry with regard to spine A. However, this symmetry is upset by the presence of spine Vert. Apophyses a of spine A and apophyses p of spines L, as well as the arches connecting them with each other or with other apophyses, are well developed. The wall of the cephalis rests on the vertical arches mp, mc and on the horizontal arches cp and pj. It is thin with numerous irregularly shaped pores. From the other extensions of the four basic spines, lateral branches disperse symmetrically and in strict order. Or these branches are nets consisting of thin, parallel filaments. These nets form three lateral and three lower plates. Each plate has three systems of such filaments, which intersect each other: some filaments extend parallel to the wall of the cephalis, others are parallel to one of the basic spines, whereas the third ones extend parallel to the other spine. Besides the basic spines and plates, the distal part of the apophyses a is also sometimes included into the plates, which leads to the impression that these are rays, extending from the cephalis.
Remarks:Haeckel distinguished the species of Callimitra by the number of rays which extend from the basic spines and are included in the plates. However, the numbers he gives (5, 6, 7, or 8 rays on lateral spines and 2, 3, 5, or 5 pairs of rays on the lower plates) are not strictly reliable even for those specimens which are shown in his figures (Haeckel, 1887a, pl. 63). A more stable feature is not the number of the rays, but the nature of the distribution of the rays and of the other bars, their intersection and so forth.
New stratigraphic range:Pleistocene (?) to Recent. Tropical areas of the World Ocean.
Subsequent descriptions:YES

Emended description:Representatives of the Plagiacanthidae which are characterized by 3 large lattice panels extending laterally from the tip of the apical apophysis to the tips of each of the frontal and primary lateral apophyses.
Remarks:This diagnosis is very close to Haeckel's (1887) original description. The distinction is that the lattice panels (vertical wings of Haeckel's nomenclature) must extend to the ends of the apophyses. Consequently, Clathromitra Haeckel, 1887a, is not synonymized here because its type species (C. pterophormis Haeckel, 1887a) bears only partial lattice panel development. All the known Callimitra species are treated below.
Stratigraphic range:Late Eocene (Thyrsocyrtis bromia Zone) to Pleistocene (Tholospyris devexa devexa Zone).
Subsequent revision:YES

Revised description:Sethoperinae with a two-segmented looking shell, made of a cephalis with 6 plates. Internal skeleton omposed by A, D and 2L spines approximately of same length. As MB is short, it seems that the spines are outgrowing from a single point, at an angle of 120° from each other. However, the symmetry of this construction is only external due to the Vert spine. Apophyses a of A spine and apophyses p of L spines are well-differentiated; they are included within the above mentioned plates. Cephalic wall delimited by the vertical arches mp and mc, and the horizontal arches cp and pj which are included in the plates. Cephalic wall thin, latticed, or perforated by many irregular pores. From the basal spines, and very regularly on each side, outgrow the lateral apophyses which constitute the frames of the plates. On these apophyses, thin threads are fixed in parallel lines. each plate has 3 systems of these threads: one parallel to the cephalis arch entering in the plate, another one parallel to the basal arches that constitute the plate, and a third one parallel to the other basal spines. This species differs from Clathrocorys in having the proximal part of the plate, close to the cephalis, often better developed than the peripheral part.
Stratigraphic range:Pleistocene ? - Recent.
Subsequent revision:?

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.
- Goll, R. M. (1979). The Neogene evolution of Zygocircus, Neosemantis and Callimitra: their bearing on nassellarian classification. A revision of the Plagiacanthoidea. Micropaleontology 25(4): 365-396.
- 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.
- Petrushevskaya, M. G. (1971b). Radiolyarii Nassellaria v planktone mirovogo okeana (Radiolarians of the Ocean). Akademiya nauk SSSR, Zoologicheskii Institut, Issledovaniya Fauny Morei 9(17): 294.
- Popofsky, A. (1913). Die Nassellarien des Warmwassergebietes. Deutsche Südpolar-Expedition, 1901-1903. E. Drygalski. Berlin, Germany, Georg Reimer. 14: 217-416.