Desmids from Thailand and Malaysia

W. & G.S.West 1902, 183, Pl.22, f.2; Krieger 1932, 195, Pl.16, f.5; Scott & Prescott
1961, 87, Pl.59, f.1.
L. 23-26 ptm, Bcpr. 28.6-31 Ltm, and I. 8.5 ptm. Sts. 19,25. Ceylon, Indonesia
(Java, Sumatra, Bali)
16. St. clepsydra Nordst. var. obtusum Nordst. Pl.37, f.8.
Thomasson 1960, Nov. Act. Reg. Soc. Sci. Upsal. ser. IV. 17:12, 26, f.9:37.
L. 35 "m, B. 38 Ltm, and I. 8.5 ptm. St. 53.
17. St. cotumbetoidesW. &G.S.West
West 1902, Trans, Linn. Soc. Bot. 6, 186, Pl.22, f.8,9; Hirano 1959, Contr. 9, 351,
Pl.44, f.1.
Lspr. 13-15 xtm, cpr. 53-66 ptm, Bspr. 13-15 ptm, cpr. 44-66 um, and I. 4.5-8
ptm. Sts. 19,24,36. Ceylon, Japan. New to Thailand.
18. St. connatum (Lund.) Roy&Bisset Pl.49, f.8.
West & Carter 1923, 5, 15, Pl.130, f.6-8; Krieger 1932, 195, Pl.14, f.4; Scott & Pre-
scott 1961, 88, Pl.53, f.12.
Lssp. 20-33 ptm, Bssp. 21-29.5 Ltm, and I. 6.5-11 um. Sts. 19,31,53. Burma,
Ceylon, Indonesia (Sumatra), Philippines, Japan, Europe, N.America, Africa, Australia.
19. St. contectum Turner Pl.39, f.2.
Turner 1892, 25, 111, Pl.15, f.20; Krieger 1932, 195, Pl.18, f.15; Scott & Prescott
1961, 88, Pl.54, f.6.
L. 27.7 ptm, B. 44 ptm, and I. 12 pm. Semicells obtriangular, lateral margin slightly
convex, apex concave, apical angles with a pair of sharp spines and with a slender pro-
cess just below the spines. St. 49. India, Burma, Indonesia (Sumatra). New to Thai-
land.
20. St. corniculatum Lund. var. spinigerum West Pl.47, f.17.
West 1892, Jour. Linn. Soc. Bot.29, 171, Pl.22, f.12; West 1911, 4, 164, Pl.125, f.19-
22; Prescott et al. 1982, 2:4, 166, Pl.336, f.6.
Lssp. 26.4 ptm, Bssp. 19.8 ptm, and I. 12.3 ptm. This variety is similar to St. un-
guiferum Turner var. inerme (Turner) West. However it differs from the latter by a
small form. St. 30. Europe, Australia, New Zealand. New to Thailand.
20a. var. variabile Nordst. Pl.38, f.2; Pl.47, f.22,23.
Krieger 1932, 196, Pl.15, f.2; Scott & Prescott 1961, 88, Pl.54, f.1-4; Prescott et al.
1982, 2:4, 166, Pl.336, f.8.
L. 26.4 ptm, B. 20-40 ptm, and I. 10-15 ptm. Cells moderate in size, deeply con-
stricted at the middle, sinus open, acute and acuminate at the extremity; semicells
obversely lunate, apex slightly convex, lateral margin convex and retuse at the middle of
the margin, apical angles with a sharp and diverging spine; vertical view of a semicell
triangular, angles rounded and with a spine, sides concave. Sts. 19,26,31,43,53. In-
donesia (Java, Sumatra, Bali). New to Thailand.