taxonID	type	description	language	source
757E87A52665FF9EFF2AFBCDFECEF942.taxon	materials_examined	Type: — JAPAN. Deep-sea sediments at the earliest Middle Miocene, 490 cm in depth of the RC 12 - 394 core, recovered from the Yamato Bank, Japan Sea (holotype MPC- 04211). Vegetative cells: Valves circular, 10 – 30 µm in diameter, striae density c. 25 – 30 in 10 µm at margin on valve face; c. 30 areolae in 10 µm, arranged radially. Valve face flattened, mantle vertical. Valve face with central hyaline area, lacking sternum; valve face and margin with internally developed radial transapical ribs and striae. Some ribs extending towards central area, some part way onto valve face, others present only at mantle. Striae composed of parallel rows of areolae. Single rimoportula, simple slit externally, located within stria, with paired lips, internally. Cingulum composed of more than 5 open copulae, band orientation at 90 o to rimoportula. Each copula with ligula and paired areolae divided by septum; areolae in parallel rows. No evidence of further band differentiation. Initial cells: Hemispherical with thin valve margin, 25 – 30 µm in diameter. Central area with irregularly arranged areolae and hyaline structures. Marginal area composed of internally developed radial costae and striae. Striae composed of parallel areolae rows, single rimoportula located within stria, structure as in vegetative valve.	en	Saito-Kato, Megumi, Hayashi, Tatsuya, Tanimura, Yoshihiro (2011): Tetracyclus radius (Bacillariophyta) a new fossil species from Miocene freshwater sediments in the Japan Sea. Phytotaxa 24: 51-57, DOI: 10.11646/phytotaxa.24.1.7, URL: http://biotaxa.org/Phytotaxa/article/view/phytotaxa.24.1.7
