Parodontella calamus (J. Tempère & Brun) Komura (1999: 60)

Sims, Pat A., Williams, David M. & Ashworth, Matt, 2018, Examination of type specimens for the genera Odontella and Zygoceros (Bacillariophyceae) with evidence for the new family Odontellaceae and a description of three new genera, Phytotaxa 382 (1), pp. 1-56 : 10

Parodontella calamus (J. Tempère & Brun) Komura (1999: 60) ( Figs 29–35 )

Basionym:— Biddulphia calamus Tempère & Brun in Brun & Tempère (1889 [1890]: 26, pl. 5, fig. 15)

Synonyms:— Odontotropis calamus (Tempère & Brun in Brun & Tempère) De Toni (1894: 881) Odontella calamus (Brun & Tempère) Schrader in Schrader & Fenner (1976: 992, pl. 20, fig. 7)

Type:— “Calcaire du Sendaï” ( Brun & Tempère (1889 [1890]: 26)

Valves broadly lanceolate with rounded apices, valve face narrowly lanceolate bordered by well-developed crenulated marginal ridge separating it from deep expanded valve mantle surrounding valve face ( Figs 29–31 ); valve length 150–185μm, breadth 60–75μm. Valve face with very narrow, short elevations at apices, each with small ocellus at summit and four stout very long spines ( Figs 30–32 ), exterior openings of rimoportulae ( Fig. 33 ). Areolae loculate with interior foramina ( Fig. 33 ) and external fine pores arranged in longitudinal rows ( Fig. 34 ) meeting centrally at sternum. Long spinules scattered on mantle ( Fig. 32 ). Rimoportulae 4, opening externally through massive spines on valve face, spines arranged one at each pole lying just within elevation, other 2 centrally touching marginal ridge ( Figs 30–32 ). Each internal opening a transapically aligned slit across a sunken papillus ( Fig. 35 ).

Observations:— The description above is based on material from Sendai, Japan ( BM 53119, BM 53120, cementstein, ‘cement and stone’, BM Adams Bess 537).

Figures

FIGURES 29–35. Parodontella calamus (Brun and Tempère) Komura (Sendai, Japan). Fig. 29. Reproduction of plate 5, fig. 15 for Biddulphia calamus from Tempère and Brun (1889 [1890]) (not to scale). Fig. 30. Tilted valve exterior with four stout spines positioned marginally on valve face, crenulated marginal ridge and deep expanded mantle; scale bar = 60 μm. Fig. 31. Valve exterior flat, with lanceolate valve face with central sternum, broad mantle extending around apices; scale bar = 43 μm. Fig. 32. Apical view with short narrow elevations at apices, four very long stout spines expanded at base and long spinules on mantle; scale bar = 43 μm. Fig. 33. Valve interior with foramina, interior and exterior openings of rimoportula and crenulated marginal ridge; scale bar = 25 μm. Fig. 34.Apical axis, mantle with radially aligned with rows of poroids between longitudinal, barely raised, costae; scale bar = 10 μm. Fig. 35. Interior, foramina and sunken papillus with central slit, which is the opening of a rimoportula; scale bar = 4.3 μm.