Actinocyclus subtilis f. subtilissima Van Heurck in Østrup, 1904 (original description)
Actinoptychus moronensis var. guttata Østrup, 1904 (original description)
Cyclophora siamensis Østrup, 1904 (original description)
Diploneis ocellata Østrup, 1904 (original description)
Euphyllodium spathulatum Østrup, 1904 (original description)
Glyphodesmis siamensis f. minor Østrup, 1904 (original description)
Glyphodesmis siamensis f. siamensis Østrup, 1904 (original description)
Hantzschia marina var. leptocephala Østrup, 1904 (original description)
Mastogloia parvula Østrup, 1904 (original description)
Mastogloia quadrinotata Østrup, 1904 (original description)
Navicula crucifera var. capitata Østrup, 1904 (original description)
Navicula decora (Greville) Østrup, 1904 accepted as
Stauroneis decora Greville, 1865 (new combination reference)
Navicula farcimen Østrup, 1904 (original description)
Navicula ocellata Østrup, 1904 (original description)
Navicula siamensis Østrup, 1904 (original description)
Navicula subglabra Østrup, 1904 (original description)
Nitzschia panduriformis var. interrupta Østrup, 1904 (original description)
Pseudoamphiprora decora (Greville) Østrup, 1904 accepted as
Stauroneis decora Greville, 1865 (new combination reference)
Rhaphoneis bilineata var. contracta (Grunow in Cleve) Østrup, 1904 (new combination reference)
Rhoicosphenia tenuissima Østrup, 1904 (original description)
Scoliopleura siamensis Østrup, 1904 (original description)
Striatella delicatula var. gibbosa Østrup, 1904 (original description)
Vanheurckia siamensis Østrup, 1904 (original description)