. Synopsis of the naviculoid diatoms. Presented to the R. Swedish Academy of Sciences May 10, 1893. Diatoms. 76 p. T. CLEVE, SYNOPSIS OF THE NAVICULOID DIATOMS. 3. C. circiimvallata Cl. N. Sp. â V. linear-elliptical with broad, rounded, sometimes slightly rostrate ends. L. 0,055 to 0,075; B. 0,oi2 to 0,022 mm. Median line slightly sigmoid, with approxi- mate central pores and prolonged terminal fissures. Axial area narrow; central rhomboidal. Ridges one or two on each side of the median line. Striee 9 in 0,oi mm., parallel, radiate at the ends, punctate; puncta coarse, forming longitudinal row
. Synopsis of the naviculoid diatoms. Presented to the R. Swedish Academy of Sciences May 10, 1893. Diatoms. 76 p. T. CLEVE, SYNOPSIS OF THE NAVICULOID DIATOMS. 3. C. circiimvallata Cl. N. Sp. â V. linear-elliptical with broad, rounded, sometimes slightly rostrate ends. L. 0,055 to 0,075; B. 0,oi2 to 0,022 mm. Median line slightly sigmoid, with approxi- mate central pores and prolonged terminal fissures. Axial area narrow; central rhomboidal. Ridges one or two on each side of the median line. Striee 9 in 0,oi mm., parallel, radiate at the ends, punctate; puncta coarse, forming longitudinal rows, 14 in 0,oi mm. â PL I f. 10, 11. Marine: Balearic Islands! Ceylon! Labuan! Japan (Brun Coll.)! Diploneis Ehb. (1840). Valve usually short, constricted in the middle, or not, generally with obtuse or rounded ends. Central nodule more or less quadrate, prolonged into horns, or processes, which enclose the median line. On both sides of the horns are depressions, or furrotvs, of more or less breadth. Structure: transverse finer strige, or coarser costaj, which usually continue in a rudimentary state across the furrows, where they frequently give rise to a longi- tudinal row of large pearls. The transverse costse are often crossed by one or more longitudinal costfe, giving the valve the appearance of being reticulated; or alternate with dotible rows of finer puncta, or alveoli. â The cell-contents (of D. fusca, D. Smithii, D. didyma, D. siibcincta, D. chersonensis and 1>. constricia) have two chromatophore-plates along the connecting zone. They are deeply in- dented and divided, sometimes in such a manner as to be split up into closely crowded and orbicular small discs. The name Diploneis was given by Ehrenberg 1840, to some panduriform navieuloid diatoms. This characteristic is of no importance; but on the other Diploneis Smithii, hand, the central nodule, the furrows and the structure are so peculiar, that the times magnified. t\- ^ â \ A A ^^ v A A genus Diploneis may b
Size: 1166px × 2143px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1890, booksubjectdiatoms, bookyear1894
