Achnanthes calcar var. australis Playfair, 1914 (original description)
Achnanthes calcar var. pulcherrima Playfair, 1914 (original description)
Amphiprora alata var. holdereri (Gutwinski) Playfair, 1914 (1915) accepted as
Amphiprora paludosa var. holdereri R.Gutwinski (new combination reference)
Amphora veneta var. grossestriata Playfair, 1914 (original description)
Cocconeis placentula var. australica Playfair, 1914 (original description)
Coscinodiscus lacustris var. denticulatus Playfair, 1914 (1915) (original description)
Coscinodiscus lacustris var. iris (Héribaud-Joseph & Brun) Playfair accepted as
Cyclotella iris f. iris Brun & Héribaud, 1893 (new combination reference)
Coscinodiscus lacustris var. papillatus Playfair, 1915 (original description)
Coscinodiscus lacustris var. pellucidus Playfair, 1915 (original description)
Coscinodiscus lacustris var. stellatus Playfair, 1915 (original description)
Coscinodiscus lacustris var. tympaniformis Playfair, 1915 (original description)
Cyclotella meneghiniana var. beta Kützing Bac. T. 30, f. 68 according to Playfair (original description)
Cyclotella meneghiniana var. brevistriata Playfair, 1914 (original description)
Cyclotella meneghiniana var. convexa Playfair, 1914 (original description)
Cyclotella meneghiniana var. fluviatilis Playfair, 1914 (original description)
Cyclotella meneghiniana var. quadrata Playfair, 1914 (original description)
Diadesmis confervacea var. peregrina (W.Smith) G.I.Playfair, 1914 accepted as
Diadesmis peregrina W.Smith, 1857 (new combination reference)
Diploneis boldtiana var. acuminata Playfair, 1914 (original description)
Diploneis boldtiana var. australica Playfair, 1914 (original description)
Diploneis boldtiana var. ovalis Playfair, 1914 (original description)
Epithemia gibberula var. perpusilla Playfair, 1914 (original description)
Eunotia formica var. richmondiae Playfair, 1914 (original description)
Gomphonema augur var. angulatum Playfair, 1914 (original description)
Gomphonema augur var. rotundatum Playfair accepted as
Gomphonema abbreviatum var. longipes Kützing, 1844 (new combination reference)
Gomphonema constrictum var. australe Playfair, 1914 (original description)
Gomphonema triangulare Playfair, 1914 (original description)
Melosira varians var. moniliformis (Otto Müller) Playfair, 1915 (new combination reference)
Navicula mutica var. ovalis Playfair, 1914 (original description)
Navicula mutica var. rhomboidea Playfair, 1914 (original description)
Navicula mutica var. subcircularis Playfair, 1914 (original description)
Navicula mutica var. subhexagona Playfair, 1914 (original description)
Nitzschia paradoxa var. perpusilla Playfair, 1915 (original description)
Nitzschia vermicularis var. minuta Playfair, 1915 (original description)
Nitzschia vermicularis var. sialis Playfair, 1915 (original description)
Surirella ovalis var. lewisii Playfair, 1915 (original description)
Surirella plana var. algensis Playfair, 1915 (original description)
Synedra lismorensis Playfair, 1915 (original description)
Tryblionella cruciata Playfair, 1915 (original description)
Tryblionella hantzschiana var. australica Playfair, 1915 (original description)
Tryblionella hantzschiana var. calida (Grunow) Van Heurck (new combination reference)
Tryblionella hantzschiana var. minor Playfair, 1915 (original description)
Tryblionella hantzschiana var. ovata (Lagerstedt) Playfair, 1915 accepted as
Tryblionella ovata Lagerstedt, 1873 (new combination reference)
Tryblionella hantzschiana var. victoriae (Grunow) Playfair, 1914 accepted as
Tryblionella victoriae Grunow, 1862 (new combination reference)
Vanheurckia cuspidata var. ambigua (Ehrenberg) Playfair, 1914 accepted as
Navicula ambigua f. ambigua Ehrenberg, 1843 (new combination reference)
Vanheurckia cuspidata var. danaica (Grunow) Playfair, 1914 accepted as
Navicula cuspidata var. danaica Grunow ms., 1894 (new combination reference)
Vanheurckia cuspidata var. kyoglensis Playfair, 1915 (original description)
Vanheurckia rhomboides f. minor Playfair, 1915 (original description)