Lophophaena cylindrica (Cleve, 1900) Petrushevskaya, 1971

Plate 22, Figs. 1A – 4.

Dictyocephalus cylindricus n. sp., Cleve, 1900, p. 7, pl. 4, fig. 10.

Lophophaena cylindrica (Cleve), Petrushevskaya, 1971, p. 117, pl. 57, fig. 5; pl. 61, figs. 4–6.

non Lophophaena cylindrica Cleve, Renz, 1976, pl. 6, fig. 21.

Lophophaena cylindrica Cleve, Takahashi, 1991, pl. 25, fig. 3 (non figs. 4–5).

Lophophaena cylindrica Cleve, Hull, 1993, pl. 4, fig. 2.

Lophophaena cylindrica Cleve, Sashida and Kurihara, 1999, fig. 7.4.

unknown plagonid group C sp 30, Trubovitz et al., 2020, supplementary data 7.

Remarks. This species is close to Lophophaena hispida (Ehrenberg) Petrushevskaya (Pl. 22, Figs. 5–8B), but differs in that pore size is consistent throughout the skeleton, whereas L. hispida has significantly larger pores on the cephalis. Well-preserved specimens of this species also tend to show an extra built-up layer of silica around the neck area, whereas L. hispida does not. The Lophophaena cylindrica specimen illustrated in Renz (1976), and some of the specimens illustrated in Takahashi (1991) appear to have large pores on the cephalis (although image quality is low), likely making these L. hispida specimens. There is significant variation in size within this species, including in our EEP material.

Range. Late Miocene—Recent, EEP (Table 1).