Desmids from Thailand and Malaysia

Desmids from Thailand and Malaysia 37
narrow-linear; semicells depressed hexagonal, apex straight, apical angles obtuse, upper
lateral margin retuse, lower margin divergent and straight. St. 44. Cosmopolitan.
84. C. portianum Arch. var. portianum Pl.19, f.9.
West 1908, 3, 165, Pl.80, f.4-7; Scott & Prescott 1961, 65, Pl.28, f.8.
L. 22-30 ptm, B. 17.6-22 ptm, and I. 6.5-9 pm. Sts. 25,26 India, Ceylon, Japan,
U.S.A., Brazil, Australia. New to Thailand.
84a. var. mojus Scott&Prescott Pl.19, f.6; Pl.20, f.6.
Scott & Prescott 1961, 65, Pl.28, f.9.
L. 41.5-60 gm, B. 31-48 ptm, and I. 12-20 ptm. Sts. 10,26. Indonesia (Java). New
to Thailand.
84b. var. nephroideum Wittr. Pl.20, f.10.
West 1908, 3, 167, Pl.80, f.10,11; Scott & prescott, 1961, 66, Pl.28, f.10; Prescott et
al. 1981, 2:3, 230, Pl.254, f.4.
L. 23-35 "m, B. 20-27 ptm, and I. 5.3-9 ptm. St. 43. Indonesia (Borneo), Japan,
Europe, Nevv to Thailand.
85. C. praecisum Borge var. suecicum (Borge) Krieger & Gerloff Pl.15, f.6.
Krieger & Gerloff 1962, Gatt[ Cosm. 1, 92, Pl.20, f.9.
L. 13 ptm, B. 13 ptm, and I. 4.5 ptm. Cells small, deeply constricted, sinus linearly
open; semicells trapeziform, apex and lateral margins straight. St. 10,11. Europe,
Malaysia.
86. C. praegrande Lund. Pl.27, f.1.
West 1908, 3, 150, Pl.77, f.19; Fdrster 1982, 239, Pl.29, f.7.
L. 96.3 ptm, B. 50.6 ptm, and I. 26.4 xtm. This species is similar to C. striolatum var.
noralstedti. However, it differs from the latter in having a different size of a cell, an
acute shaped sinus, and conical granules that covered all the face of a semicell. St. 1.
Europe, Greenland. New to Thailand.
87. C. prominens Turner Pl.18, f.19.
Krieger & Gerloff 1965, Gatt. Cosm. 2, 220, Pl.40, f.18.
88.
89.
L. 11 xtm, B. 10.5 ptm, and I. 2.5 ptm. Cells minute, slightly broader than the
length, deeply constricted at the middle, sinus closed; side view of a semicell circular
with a papilla on each side; vertical view elliptic with a papilla on each side of semicell.
St. 35. India. New to Thailand.
Cpseudamoenum Wille Pl.18, f.28.
West 1911, 4, 31, Pl.102, f.7-9; FOrster 1982, 242, Pl.29, f.9.
L. 62 ptm, B. 26.4 #m, and I. 17.6 ptm. Sts. 25,28,30. Japan, Europe, N. & S.Amer-
ica, Africa. New to Thailand.
C. pseudarctoum Nordst.
West 1908, 3, 32, Pl.68, f.12-14, Pl.72, f.40,41; F6rster 1982, 242, Pl.19, f.7-13.
L. 13.2 ptm, B. 9.7 ptm, and I. 8.5 ptm. Sts. 36,49. Japan, Thailand, Europe, Spitz-