Belongs within: Bacillariophycidae.
Diploneis is a genus of solitary diatoms with elliptical or panduriform frustules (Crosby & Ferguson Wood 1959).
Characters (Crosby & Ferguson Wood 1959): Cells solitary; frustules in valve view elliptical or panduriform. Dividing bands and septa absent; central area enclosed in strongly siliceous horns; central nodule quadrate; valves costate, striate or both; sulci and sometimes lunulae present outside siliceous horns; poroids (areolae) between transverse apical costae in single or multiple rows (usually double); plastids two.
<==Diploneis Ehrenberg 1844G75
|--D. adonis (Brun.) Cleve 1894CFW59
| |--D. a. var. adonisCFW59
| `--D. a. var. oamaruensis Cleve 1894 [=Navicula oamaruensis; incl. N. apis]CFW59
|--D. advena (A.S.) Cleve 1894 [=Navicula advena A.S. 1875]W61a
|--D. beyrichiana A.S. 1881W61a
|--‘Navicula’ biconstricta Gr. & St. 1887CFW59
|--D. bombus Ehrenberg 1844W61a
| |--D. b. var. bombusW61a
| |--D. b. var. bombiformis (Cleve) Hust. 1933 [=D. bombiformis Cleve 1894]W61a
| |--D. b. var. bullataM01
| `--D. b. var. densestriataM01
|--D. campylodiscus (Grun.) Cleve 1894W61a (see below for synonymy)
|--D. chersonensis (Grun.) Cleve 1891 [=Navicula chersonensis Grun. in A.S. 1876]CFW59
|--D. coffaeiformis (A.S.) Cleve 1894CFW59
|--D. contiguaM01
| |--D. c. var. contiguaM01
| `--D. c. var. eudoxiaM01
|--D. crabro Ehrenberg 1854 [=Navicula crabro]CFW59
| |--D. c. var. crabroCFW59
| `--D. c. var. pandura (Brebisson) Cleve 1894 [=Navicula pandura Brebisson 1854]CFW59
|--D. cythniaG75
| |--D. c. var. cythniaG75
| `--D. c. var. mediterranea (Grunow) Hustedt 1927–1964G75
|--‘Navicula’ diconstrictaCFW59
|--D. didymaG75
|--D. finnica (Ehrenberg) Cleve 1891 [=Cocconeis finnica Ehrenberg 1838]W61a
|--D. fusca (Greg.) Cleve 1894 [=Navicula fusca Ralfs in Pritch. 1861]CFW59
| |--D. f. var. fuscaCFW59
| `--D. f. var. aestiva (Donkin) Hust. 1933 [=Navicula aestiva Donkin 1858]CFW59
|--D. gemmata (Greville) Cleve 1894W61a [=Navicula gemmata Greville 1859W61a; incl. N. gemmata var. mediterraneaCFW59]
| |--D. g. var. gemmataW61a
| `--D. g. var. pristiophora (Jan.) Cleve 1894 [=Navicula pristiophora Jan. in A.S. 1881]W61a
|--D. gemmatula (Grun.) Cleve 1894 [incl. Navicula entomon Ehrenberg in Kützing 1844]CFW59
|--D. graeffii (Grun.) Cleve 1894 [=Navicula graeffii Grun. in A.S. 1875]CFW59
|--D. gruendlerii (A.S.) Cleve 1894 [=Navicula gruendleri A.S. 1873]CFW59
|--‘Navicula’ hyalina Kützing 1894 (n. d.)G75
|--D. incurvata (Greg.) Cleve 1894 [=Navicula incurvata Greg. 1856]CFW59
|--D. interrupta (Kützing) Cleve 1894 [=Navicula interrupta Kützing 1844]W61a
| |--D. i. var. interruptaCFW59
| `--D. i. var. clancula (A.S.) Cleve 1894 [=Navicula clancula A. S. 1875]CFW59
|--D. litoralis (Donkin) Cleve 1894G75 [incl. Navicula ovulum Grun. 1860CFW59]
|--D. lobata Gr. & St. 1877 [=Navicula lobata Gr. & St. 1887; incl. N. spathifera]CFW59
|--D. nitescens (Greg.) Cleve 1894 [=Navicula nitescens Ralfs in Pritch. 1861, D. smithii var. nitescens]CFW59
|--D. notabilis (Greville) Cleve 1894W61a
| |--D. n. var. notabilisG75
| `--D. n. var. oblonga Heiden & Kolbe 1928G75
|--D. novae-zeelandiae (A.S.) Hust. 1933 [=Navicula interrupta var. novae-zeelandiae]CFW59
|--D. ovalisG63
| |--D. o. var. ovalisG63
| `--D. o. var. oblongellaG63
|--D. papula [=Navicula papula]G75
|--D. pseudovalisG63
|--D. rostrata Wood 1961W61a
|--D. smithii (Brebisson) Cleve 1894 (see below for synonymy)CFW59
| | i. s.: D. s. f. cuneataG63
| | D. s. f. rhombica Mereschowsky 1902CFW59
| |--D. s. var. smithiiG63
| `--D. s. var. constrictaG63 [=Navicula constricta Grun. 1860CFW59, D. constricta (Grun.) Cleve 1894CFW59]
|--D. splendens (Greg.) Cleve 1894 [=Navicula splendida Greg. 1856 non Ehrenberg 1838]CFW59
|--D. splendidaM01
| |--D. s. var. splendidaM01
| `--D. s. var. puellaM01
|--D. suborbicularisW61a
| |--D. s. var. suborbicularisG63
| `--D. s. var. africana Cholnoky 1960G63
|--D. subovalis Cleve 1894G63
|--D. vacillans (A. S.) Cleve 1894 [=Navicula vacillans A. S. 1875]CFW59
| |--D. v. var. vacillansM01
| |--D. v. var. delicatulaM01
| `--D. v. var. renitensG63
|--D. vetulaG75
| |--D. v. var. vetulaG75
| `--D. v. var. americana Hustedt 1955G75
| |--D. v. var. a. f. americanaG75
| `--D. v. var. a. f. minutissima Hustedt 1955G75
`--D. weissflogi (A.S.) Cleve 1894 [=Navicula weissflogi A.S. 1875; incl. N. diversa Grev. 1863]CFW59
Diploneis campylodiscus (Grun.) Cleve 1894W61 [=Navicula campylodiscus Grun. in A.S. 1875W61; incl. Cocconeis caelata Arnott 1868CFW59]
Diploneis smithii (Brebisson) Cleve 1894 [=Navicula smithii Brebisson in W. Sm. 1856; incl. N. smithii var. minor Petit 1877 non West 1812]CFW59
*Type species of generic name indicated
References
[CFW59] Crosby, L. H., & E. J. Ferguson Wood. 1959. Studies on Australian and New Zealand diatoms. II.—Normally epontic and benthic genera. Transactions of the Royal Society of New Zealand 86 (1): 1–58, pls 1–9.
[G63] Giffen, M. H. 1963. Contributions to the diatom flora of South Africa. I. Diatoms of the estuaries of the eastern Cape Province. Hydrobiologia 21: 201–265.
[G75] Giffen, M. H. 1975. An account of the littoral diatoms from Langebaan, Saldanha Bay, Cape Province, South Africa. Botanica Marina 18: 71-95.
[M01] Mereschkowsky, C. 1901. A list of Californian diatoms. Annals and Magazine of Natural History, series 7, 7: 292–300.
[W61] Wood, E. J. F. 1961. Studies on Australian and New Zealand diatoms. IV.—Descriptions of further sedentary species. Transactions of the Royal Society of New Zealand 88 (4): 669–698.