Key To Species

la. Bands indistinct or not resolved in water mounts, conspicuous wing-like extensions of elevations 2

lb. Bands distinct, elevations and wings inconspicuous, valve margin dentate, labiate process submarginal, areola array fan shaped and oriented toward the process C. dentata Hasle in Hasle 8c Syvertsen

2a. Broad wing-like extensions of the elevations fitting into V-shaped deep furrows on mantle of adjacent valve, labiate process marginal, areola array irregular

C. bicornisn (Ehrenberg) Hasle in Hasle 8c Sims

2b. Wing-like extensions of elevations less conspicuous, labiate process central or subcentral, regular areolae rows oriented toward the process

C. pelagica (Cleve) Hendey

Distribution:

C. bicornis and C. dentata—coastal warm water region.

C. pelagica—cosmopolitan. How to identify: The species may be identified in girdle view in water mounts. In critical cases examination of valve structure made on cleaned material mounted in a medium of a high refractive index may be necessary. Remarks: Cerataulina bicornis is the only species of the genus that has been found with resting spores. These are morphologically distinctly different from the vegetative cells and were described as Syringidium bicornis (Ehrenberg, 1845a; Hasle 8c Sims, 1985).

11 Basionym: Syringidium bicorne Ehrenberg. Synonyms: Cerataulina compacta Ostenfeld in Ostenfeld & Schmidt; Cerataulina daemon (Greville) Hasle in Hasle & Syvertsen.

TABLE 39 Morphometric Data of Climacodium spp. (Hustedt, 1930)

Pervalvar Apical

C. biconcavum ca. 60 35-65

C. frauenfeldianum 10-30 75-225

Genus Climacodium Grunow 1868 (Plate 33, Table 39) Type: Climacodium frauenfeldianum Grunow.

References: Grunow, 1868, p. 102, Plate la, Fig. 24; Cleve, 1897a, p. 22, Plate 2, Figs. 16 and 17; Hustedt, 1930, p. 776, Figs. 453 and 454; Cupp, 1943, p. 147, Fig. 105.

Generic characters:

Cells straight but usually forming somewhat twisted chains.

Valves elliptical.

Apertures between cells in chains large. KEY TO SPECIES

la. Valve surface between elevations flat, apertures right angled to oblong and larger in pervalvar direction than in the cell proper

C. frauenfeldianum Grunow lb. Valve surface between elevations concave, apertures elliptical lanceolate, usually smaller than the cell proper C. biconcavum Cleve

Distribution: Warm water region.

How to identify: The species may be identified as colonies or whole cells in water mounts.

Genus Eucampia Ehrenberg 1839 (Plates 33, 34, and 35, Table 40) Type: Eucampia zodiacus Ehrenberg.

References: Ehrenberg, 1841a, p. 151, Plate 4, Fig. 8; Cleve, 1873a, p. 7, Plate 1, Fig. 6; Van Heurck, 1880-1885, Plate 95 bis, Fig. 5; Cleve, 1896a, p. 10,

PLATE 34 Eucampia cornuta: (a and b) two chains of unequal width in girdle view. Scale bar = 10 p.m; (c) valve in girdle view; (d) valve in valve view (central labiate process). Scale bar = 10 fim; (e) costate ocellus. Scale bar = 1 ¿im. Eucampia groenlandica: (a-c) chains in broad and (d) narrow girdle views. Scale bar =10 /¿.m; (e) valve with central labiate process. Scale bar = 10 /¿m; (f) costate ocellus. Scale bar = 1 p.m. From Syvertsen 8c Hasle (1983).

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