Ceratocyrtis robustus Bjørklund, 1976

Ceratocyrtis robustus n. sp., Bjørklund, 1976, pl. 17, figs. 6–10.

non Ceratocyrtis robustus Bjørklund, Nishimura, 1990, pl. 20, fig. 6.

Ceratocyrtis robustus Bjørklund, Renaudie, 2014, pl. 18, figs. 3A–B.

non Ceratocyrtis robustus Bjørklund, Chen et al., 2017, pl. 73, figs. 20–22.

Remarks. None of the type specimens illustrated by Bjørklund (1976) clearly show the outer wall of the thorax, making it difficult to visualize the nature of the pores on that part of the shell, which are described by the author as “rounded to irregularly rounded pores of variable size, 5–25 µm.” Both Nishimura (1990) and Chen et al. (2017) depict specimens with pores of fairly consistent size; small pores are visible on the specimen in Nishimura (1990) and large pores on both specimens in Chen et al. (2017). Thus, these specimens are excluded from our synonymy, and further illustration of the type material would likely aid in clarifying this species concept.