. Fresh-water biology. Freshwater biology. 132 FRESH-WATER BIOLOGY 52 (51, 53) Characteristics similar to those of Dialoma except that the cells are borne in ribbons. Denticula KUtzing. The vajves are marked by heavy ribs which are in reaUty shallow septa, between which are delicate striae, iiiiiiiii't Denticula occurs on wet rocks and in fresh water; sometimes also in """"""I brackish water. Fig. 96. Denticula injlata Smith, a. Valve side. 6. girdle side. X 600. (Original.) S3 (Si; 52) Characteristics as in Denticula except that the striations are in- terrupted i
. Fresh-water biology. Freshwater biology. 132 FRESH-WATER BIOLOGY 52 (51, 53) Characteristics similar to those of Dialoma except that the cells are borne in ribbons. Denticula KUtzing. The vajves are marked by heavy ribs which are in reaUty shallow septa, between which are delicate striae, iiiiiiiii't Denticula occurs on wet rocks and in fresh water; sometimes also in """"""I brackish water. Fig. 96. Denticula injlata Smith, a. Valve side. 6. girdle side. X 600. (Original.) S3 (Si; 52) Characteristics as in Denticula except that the striations are in- terrupted in the middle Odontidium KUtzing. Many place the members of this genus with Dialoma, while others regard the interrupted striae and the formation of shoirt fila- ments instead of zig-zag chains, sufficient differences to place them in a separate genus. Fig. 97. a, b. Odontidium mutabile Smith, c, Odontidium tabetlaria Smith. X 570. (Original.). S4 (so) Valves asymmetrical with reference to a transverse axis. Family Meridionaceae. Only one genus Meridian Agardh. Both valve and girdle sides wedge-shaped, forming ring- like or fan-shaped bands; striations uninterrupted. There are imperfect transverse septa which are con- spicuous on the valve side but show only laterally on the girdle side. Between these on the valve side are fine punctate striae. Van Heurck thinks this genus ought to be suppressed. It differs from Dialoma only in the cuneate shape of the Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Ward, Henry Baldwin, 1865-1945; Whipple, George Chandler, 1866-1924. joint author. New York, John Wiley & sons, inc. ; [etc. ,etc. ]
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectfreshwa, bookyear1918
