[ref. ID; 890]
With shell. The strength of the shell which is dependent on the arrangement of particles and the binding matrix. Three categories are readily identified, robust, intermediate and fragile. Species with robust shells often have irregular outlines as in D. oblonga. They appear to be non-selective with regards to size or shape of particles, often assembling these materials to be more than one layer deep, and rarely are areas of organic cement seen as part of the surface pattern. Those in intermediate category are probably the largest group and include D. pyriformis, D. gigantea, D. claviformis and others that construct smooth or regular shells and have areas of organic cement showing as part of the surface pattern. Those of fragile category include D. bacillariarum, D. bacillifera, D. brevicolla and D. lacustris, have shells that are fragile or delicate. The shells are constructed mainly of diatom frustules. (ref. ID; 890)

The choice of shell materials influenced of pH. (Heal, 1961)

[ref. ID; 1618]
Test variable in shape, but generally circular in cross-section; composed of cemented quartz-sand, diatoms, and other foreign bodies; aperture terminal; often with zoochlorellae; cytoplasmic body almost fills the test; typically a single nucleus; many contractile vacuoles; pseudopodia cylindrical, simple or branching; end rounded or pointed; fresh water, woodland soil, etc. (ref. ID; 1618)

[ref. ID; 1923]
Shell varying from globular to elongated pyriform or acuminate. Aperture without diaphragm. (ref. ID; 1923)

[ref. ID; 3686]
Shell colourless, yellow or brown; circular, ovoid, pyriform or acuminate; composed of agglutinated mineral particles and diatom-frustules; aperture terminal, circular or lobed, sometimes with an organic border. (ref. ID; 3686)

• Difflugia acanthophora Ehrenberg, 1841
  See; Euglypha acanthophora (ref. ID; 1332)
• Difflugia acropodia Hertwig-Lesser (ref. ID; 2489, 3693)
  Syn; Phyrganella hemisphaerica Penard (ref. ID; 2489)
• Difflugia aculeata Perty, 1849 (ref. ID; 1315) reported year? (ref. ID; 3693)
  See; Centropyxis aculeata (Ehrenberg, 1830) Stein, 1859 (ref. ID; 1315, 3693)
• Difflugia acuminata Ehrenberg, 1838 (ref. ID; 1316, 1923, 1986, 2024, 2027, 2067, 2109, 2125, 2147, 2150, 2239, 2330, 2356, 2456, 2564, 3173, 3686) reported year? (ref. ID; 2683, 3496, 3501, 3595, 3693) reported author and year? (ref. ID; 2770)
  Syn; Difflugia acaulis Perty, 1849 (ref. ID; 1316); Difflugia acuminata var. acaulis Perty, 1852 (ref. ID; 1316); Difflugia mitriformis var. acuminata Wallich, 1864 (ref. ID; 1316)
• Difflugia acuminata f. curvicaulis Penard (ref. ID; 2352)
  Syn; Difflugia curvicaulis Penard, 1902 (ref. ID; 2352)
• Difflugia acuminata f. inflata Penard (ref. ID; 2352), var. inflata Penard, 1899 (ref. ID; 1316, 2109) reported year? (ref. ID; 3501, 3693)
  Syn; Difflugia acuminata var. amphora Penard, 1890 (ref. ID; 1316); Difflugia proteiformis var. acuminata Wallich, 1863 (ref. ID; 1316)
• Difflugia acuminata var. acaulis (ref. ID; 2027)
• Difflugia acuminata var. brevicaulis Thomas & Mabille (ref. ID; 2152)
• Difflugia acuminata var. curvata Cash (ref. ID; 1316, 3595, 3686)
• Difflugia acuminata var. gigantea Chardez, 1958 (ref. ID; 2147)
  See; Difflugia giganteacuminata Chardez, 1984 (ref. ID; 2151)
• Difflugia acuminata var. magna Deflandre (ref. ID; 2125, 2147, 2152)
• Difflugia acuminata var. umbilicata Penard, 1902 (ref. ID; 3693 original paper)
• Difflugia acutissima Deflandre (ref. ID; 2125)
• Difflugia adunca Ehrenberg, 1872
  See; Cyphoderia ampulla (ref. ID; 1332)
• Difflugia alabamensis Ehrenberg, 1871
  See; Cyphoderia ampulla (ref. ID; 1332)
• Difflugia algaephila Decloitre (ref. ID; 2525 original paper)
• Difflugia alveolata Pritchard, 1861
  See; Euglypha tuberculata (ref. ID; 1332)
• Difflugia amphora (Leidy) (ref. ID; 1308, 2067, 2234, 2330, 3190, 3693)
• Difflugia amphora var. acollis Schonborn, 1965 (ref. ID; 2109 original paper)
• Difflugia amphora var. africana Van Oye, 1931 (ref. ID; 2109)
• Difflugia amphoralis (Leidy) Hopkinson (ref. ID; 2125, 2147)
• Difflugia ampla Rampi. (ref. ID; 3501)
• Difflugia ampulla Ehrenberg, 1840
  See; Cyphoderia ampulla (ref. ID; 1332), Cyphoderia margaritacea (ref. ID; 3693)
• Difflugia annulata Ehrenberg?, 1871
  See; Nebela tenella (ref. ID; 1316)
• Difflugia apiculata Cash (ref. ID; 1316)
• Difflugia apiculata var. curvata Decloitre (ref. ID; 2511 original paper)
• Difflugia arcella Wallich, 1864
  See; Arcella vulgaris (ref. ID; 1315)
• Difflugia arcula Leidy, 1879 (ref. ID; 1316) reported year? (ref. ID; 1618, 3501, 3693)
  See; Trigonopyxis arcula
  Syn; Trigonopyxis arcula (Leidy) Penard (ref. ID; 2580)
• Difflugia areolata Ehrenberg, 1841
  See; Euglypha tuberculata (ref. ID; 1332)
• Difflugia assulata Ehrenberg, 1871
  See; Quadrula symmetrica (ref. ID; 1316, 3693)
• Difflugia assulina seminulum Ehrenberg, 1871
  See; Assulina seminulum (ref. ID; 1332)
• Difflugia asterisca Rhumbler (ref. ID; 3693)
• Difflugia avellana Penard, 1890 (ref. ID; 3686) reported year? (ref. ID; 2067, 2333, 3693)
• Difflugia avellana var. gigas Gauthier-Lievre & Thomas, 1958 (ref. ID; 2109)
• Difflugia bacillariarum Perty, 1849 (ref. ID; 890, 1316, 2067, 3686) reported year? (ref. ID; 2683, 3595)
  Syn; Difflugia Solowetzkii G. S. West, 1903 (ref. ID; 1316); Difflugia acuminata var. elegans G. S. West, 1901 (ref. ID; 1316); Difflugia elegans Penard, 1890 (ref. ID; 1316)
• Difflugia bacillariarum var. elegans (Penard, 1890) Cash (ref. ID; 1316)
  Syn; Difflugia Solowetzkii Averintzev, 1906 (ref. ID; 1316)
• Difflugia bacillifera Penard, 1890 (ref. ID; 890, 1316, 1923, 2147, 2444, 2498, 3686, 3693, 4664)
  Syn; Difflugia pyriformis var. bacillifera Levander, 1895 (ref. ID; 1316); Difflugia septentrionalis var. bacillifera Averintzev, 1900 (ref. ID; 1316)
• Difflugia bacillifera Penard, 1902
  See; Difflugia pyriformis f. bacillifera (ref. ID; 2352)
• Difflugia bacillifera var. angustus Chardez, 1991 (ref. ID; 2392)
• Difflugia baculosa Schonborn, 1965 (ref. ID; 2109 original paper)
• Difflugia baradlana Varga (ref. ID; 5034 original paper) reported author and year? (ref. ID; 3370)
• Difflugia barbata Leidy, 1874
  See; Nebela barbata (ref. ID; 1316)
• Difflugia beyensi Chardez (ref. ID; 2125)
• Difflugia bicruris Gauthier-Lievre & Thomas, 1958 (ref. ID; 3299) reported year? (ref. ID; 2147)
• Difflugia bidens Penard, 1902 (ref. ID; 3693 original paper)
• Difflugia binucleata Penard, 1902 (ref. ID; 3693 original paper)
• Difflugia bombycina Grandori (ref. ID; 3383)
• Difflugia brevicolla Cash, 1909 (ref. ID; 2109) reported year? (ref. ID; 1316, 3595)
• Difflugia brevicolla Cash & Hopkinson, 1909 (ref. ID; 890, 2356, 2379)
• Difflugia brevicolla var. major Gauthier-Lievre & Thomas, 1958 (ref. ID; 2356)
• Difflugia bryophila (Penard) Jung (ref. ID; 2099, 2147, 2160, 2456)
  See; Difflugia pyriformis f. bryophila (ref. ID; 2352)
• Difflugia bulla Decloitre (ref. ID; 3383)
• Difflugia cancellata Ehrenberg, 1848
  See; Nebela collaris (ref. ID; 1316)
• Difflugia capreolata Penard, 1902 (ref. ID; 2109, 2352, 3693 original paper)
• Difflugia carinata Archer, 1867 (ref. ID; 1316) reported year? (ref. ID; 3693)
  See; Nebela carinata (ref. ID; 1316, 3693)
• Difflugia carinata Leidy
  See; Nebela merginata (ref. ID; 1316)
• Difflugia carinata Van Oye, 1956 (ref. ID; 2233 original paper)
• Difflugia carolinensis Ehrenberg, 1871
  See; Quadrula symmetrica (ref. ID; 1316)
• Difflugia carpio Ehrenberg, 1854
  See; Nebela collaris (ref. ID; 1316)
• Difflugia cassis Wallich
  See; Difflugia constricta Ehrenberg (ref. ID; 3693)
• Difflugia cellulifera Ehrenberg, 1874
  See; Nebela collaris (ref. ID; 1316)
• Difflugia ciliata Ehrenberg, 1848
  See; Euglypha ciliata (ref. ID; 1332, 3693), Euglypha compressa (ref. ID; 3693)
• Difflugia claviformis (Penard, 1899) (ref. ID; 3686) or (Penard, 1899) Ogden (ref. ID; 2022, 2024, 2152)
• Difflugia collaris Ehrenberg, 1848
  See; Nebela collaris (ref. ID; 1316, 3693)
• Difflugia collaris Leidy
  See; Nebela tubulosa (ref. ID; 1316)
• Difflugia compressa (ref. ID; 2067)
• Difflugia compressa Carter, 1864
  See; Difflugia pyriformis f. compressa (ref. ID; 2352), Pontigulasia compressa (ref. ID; 1316)
• Difflugia compressa Leidy (ref. ID; 3496) or (Leidy) Gauthier-Lievre & Thomas (ref. ID; 2147, 2152)
• Difflugia compressa var. africana Gauthier-Lievre & Thomas, 1958 (ref. ID; 2441)
• Difflugia compressa var. minima Schonborn, 1965 (ref. ID; 2109 original paper)
• Difflugia constricta Ehrenberg (ref. ID; 1618, 3693) or (Ehrenberg, 1841) Leidy, 1879 (ref. ID; 1316, 2367)
  See; Centropyxis constricta (Ehrenberg)
  Syn; Difflugia cassis Wallich (ref. ID; 3693); Difflugia constricta Certes, 1889 (ref. ID; 1316); Difflugia marsupiformis Butschli, 1880 (ref. ID; 1316) or Wallich (ref. ID; 3693); Difflugia platystoma Penard, 1890 (ref. ID; 1316) reported year? (ref. ID; 3693); Difflugia proteiformis marsupiformis Wallich, 1864 (ref. ID; 1316); Difflugia proteiformis marsupiformis var. cassis Wallich, 1864 (ref. ID; 1316)
• Difflugia constricta var. spinifera Playfair, 1918 (ref. ID; 1333)
  Syn; Echinopyxis acuelata Carter, 1864 (ref. ID; 1332); Difflugia constricta Leidy, 1874 (ref. ID; 1333); Difflugia marsupiformis Wallich, 1864 (ref. ID; 1333)
• Difflugia corana Wallich (ref. ID; 2147)
• Difflugia corona (ref. ID; 2067)
• Difflugia corona (Leidy) (ref. ID; 1308)
• Difflugia corona Wallich, 1864 (ref. ID; 1316, 1923, 1986, 2109, 2125, 2352, 2356, 3686) reported year? (ref. ID; 1618, 3496, 3693)
  Syn; Corona cornula Vejdovsky, 1881 (ref. ID; 1316); Difflugia acuminata var. furcata Daday, 1892 (ref. ID; 1316); Difflugia proteiformis globularis var. corona Wallich, 1864 (ref. ID; 1316)
• Difflugia corona var. ecornis G.-Lievre & Thomas, 1958 (ref. ID; 2067, 2110)
• Difflugia crassa Cash (ref. ID; 1316, 3595)
• Difflugia cratera Leidy, 1877
  See; Codonella cratera (ref. ID; 4609, 4613)
• Difflugia cratera Leidy, 1879
  See; Tintinnopsis cratera (ref. ID; 3280)
• Difflugia curvicaulis Penard, 1899 (ref. ID; 3173, 3686, 3693) or 1902 (ref. ID; 1316, 2024, 2125, 2147, 2152)
  See; Difflugia acuminata f. curvicaulis (ref. ID; 2352)
• Difflugia curvicaulis Penard var. inflata Decloitre (ref. ID; 3595)
• Difflugia cylindrus (Thomas) Ogden, 1983 (ref. ID; 2151, 2152)
  Syn; Difflugia oblonga var. cylindrus Thomas, 1953 (ref. ID; 2151); Difflugia pyriformis var. cylindrus (Thomas) Chardez & Decloitre, 1973 (ref. ID; 2151)
• Difflugia delicatula Gatuhier-Lieve & Thomas (ref. ID; 3496)
• Difflugia diatomosus Chardez & Gasper, 1976 (ref. ID; 2147, 2150 original paper, 2152)
• Difflugia distenda Ogden (ref. ID; 2125)
• Difflugia dujardini Chardez (ref. ID; 2147)
• Difflugia eidyi Wailes, 1913 (ref. ID; 2235)
• Difflugia elegans (ref. ID; 2027, 2067)
• Difflugia elegans Leidy, 1874
  See; Hyalosphenia elegans (ref. ID; 1316)
• Difflugia elegans Penard, 1890 (ref. ID; 1401, 2024, 2066, 2068, 2109, 2126, 2147, 2152, 2329, 2356, 2441, 2456, 3568, 3686, 3693)
• Difflugia elegans f. bicornis Jung, 1936 (ref. ID; 3568), var. bicornis Jung, 1936 (ref. ID; 2126, 2152)
• Difflugia elegans Penard f. major Tarnogradsky, 1961 (ref. ID; 3501 original paper), var. major Tarnogradsky, 1961 (ref. ID; 3568)
• Difflugia elegans f. tricornis Jung, 1936 (ref. ID; 2067, 3568), var. tricornis Jung, 1936 (ref. ID; 2126)
• Difflugia elegans var. angustata Deflandre, 1926 (ref. ID; 2126, 2564, 3568)
• Difflugia elegans var. lepida Schonborn, 1966 (ref. ID; 2066 original paper, 2126, 3568)
• Difflugia elegans var. parva Chardez, 1969 (ref. ID; 2126, 2555, 3568)
• Difflugia elegans var. teres Penard, 1899 (ref. ID; 2027, 2077, 2109, 2126, 2147, 3568) reported year? (ref. ID; 3501, 3693)
• Difflugia elisa Penard, 1893
  See; Pontigulasia elisa (ref. ID; 1316), Pontigulasia incisa (ref. ID; 3693)
• Difflugia elongata Penard, 1905 (ref. ID; 3173)
• Difflugia enchelys Ehrenberg, 1838
  See; Trinema enchelys (ref. ID; 1332, 3693)
• Difflugia enchelys Schneider, 1854
  See; Microgromia socialis (ref. ID; 1332)
• Difflugia equicalceus Leidy, 1874
  See; Nebela equicalceus (ref. ID; 1316)
• Difflugia exigua Schonborn, 1966 (ref. ID; 2066 original paper)
• Difflugia fallax Penard, 1890 (ref. ID; 1401, 2304) reported year? (ref. ID; 3693)
• Difflugia finstertaliensis Laminger, 1971 (ref. ID; 2125, 2151) or Lasinger (ref. ID; 2152)
• Difflugia flabellulum Leidy, 1874
  See; Nebela flabellulum (ref. ID; 1316)
• Difflugia foissneri Chardez, 1987 (ref. ID; 2125 original paper)
• Difflugia fragosa Hempel (ref. ID; 3693)
• Difflugia geosphaira Ogden, 1991 (ref. ID; 4799 original paper)
• Difflugia gigantea Chardez, 1984 (ref. ID; 2022, 2125, 2151 original paper, 2152)
• Difflugia giganteacuminata Chardez, 1984 (ref. ID; 2125, 2151 original paper, 2152)
  Syn; Difflugia acuminata var. gigantea Chardez, 1958 (ref. ID; 2151)
• Difflugia gigas Jung (ref. ID; 2152)
• Difflugia glans Penard, 1902 (ref. ID; 1401, 2456, 3693 original paper)
• Difflugia globularis Wallich (ref. ID; 3693) or (Wallich, 1864) Leidy, 1877 (ref. ID; 2027, 2109, 2147, 2152, 2356)
  See; Difflugia globulosa (ref. ID; 3693)
• Difflugia globularis var. sphaerica Chardez, 1956 (ref. ID; 2067, 2147, 2456)
  See; Difflugia rotunda (ref. ID; 2151)
• Difflugia globulosa (ref. ID; 2027)
• Difflugia globulosa Dujardin, 1837 (ref. ID; 3686, 3693) or 1841 (ref. ID; 2068, 2077, 2121, 2329, 2330, 2538, 2541) reported year? (ref. ID; 5034)
  Syn; Difflugia globularis Wallich (ref. ID; 3693); Difflugia proteiformis Ehrenberg (ref. ID; 3693)
• Difflugia globulosa (Ehrenberg) Hopkinson (ref. ID; 2144, 2538)
• Difflugia globulosa Leidy, 1879 (ref. ID; 1308)
  See; Phryganella acropodia (ref. ID; 1316)
• Difflugia globulosa Dujardin, 1837 sensu f. genuina Penard, 1902 (ref. ID; 4664)
• Difflugia globulus (Ehrenberg) Hopkinson (ref. ID; 1316, 2027, 2067, 2151, 2456, 2538)
  Syn; Difflugia globosa Goldsmidt, 1904 (ref. ID; 1316); Difflugia globularis Leidy, 1871 (ref. ID; 1316); Difflugia globulosa (Dujardin) Leidy, 1879 (ref. ID; 1316); Difflugia proteiformis globularis Wallich, 1864 (ref. ID; 1316)
• Difflugia globuspina (ref. ID; 2522)
• Difflugia gramen Penard, 1902 (ref. ID; 1316, 1986, 2067, 2109, 2234, 2330, 3686, 3693 original paper) reported year? (ref. ID; 2683, 3595)
  Syn; Difflugia lobostoma Leidy (ref. ID; 1316, 3693)
• Difflugia gramen Penard var. achlora Penard (ref. ID; 3595, 3693)
• Difflugia gracilis Ehrenberg, 1872
  See; Pseudodifflugia gracilis (ref. ID; 1332)
• Difflugia helix Cohn, 1853
  See; Lesquereusia spiralis (ref. ID; 1316, 3693)
• Difflugia histrio Penard, 1908 (ref. ID; 2109)
• Difflugia hyalina Schlumberger, 1854
  See; Lecythium hyalinum (ref. ID; 1332)
• Difflugia hyalina Schneider, 1854
  See; Pamphagus hyalinus (ref. ID; 3693)
• Difflugia hydrostatica (ref. ID; 5388)
• Difflugia hydrostatica Zacharias var. lithophila Penard, 1902 (ref. ID; 3693 original paper) reported year? (ref. ID; 3501)
• Difflugia kempnyi Stepanek, 1953 (ref. ID; 2151)
• Difflugia labiosa Wailes, 1919 (ref. ID; 3686) reported year? (ref. ID; 1333, 2125)
  Syn; Difflugia amphora Penard, 1901 (ref. ID; 1333)
• Difflugia lacustris (Penard, 1899) (ref. ID; 890, 2027, 2147) or (Penard) Jung (ref. ID; 2460, 3562)
• Difflugia lagena Ehrenberg, 1841
  See; Cyphoderia ampulla (ref. ID; 1332)
• Difflugia lageniformis Butschli, 1880
  See; Difflugia urceolata (ref. ID; 1316)
• Difflugia lageniformis Wallich
  See; Difflugia urceolata (ref. ID; 3693)
• Difflugia lanceolata Penard, 1890 (ref. ID; 1316, 2027, 2109, 2152, 2330, 2356, 2441, 2558, 3686) reported year? (ref. ID; 3693) reported author and year? (ref. ID; 2770)
  Syn; Difflugia acuminata Leidy i.p., pl. X, fig. 17 (ref. ID; 3693)
• Difflugia lanceolata f. hellebauti Chardez & Gasper, 1976 (ref. ID; 2027, 2150 original paper), var. hellebauti Chardez (ref. ID; 2152)
• Difflugia lata Jung (ref. ID; 2152)
• Difflugia laxa Ehrenberg, 1871
  See; Nebela collaris (ref. ID; 1316)
• Difflugia lebes Penard, 1899 (ref. ID; 1923, 2067, 2077) reported year? (ref. ID; 3693)
  Syn; Difflugia urceolata var. lebes Penard, 1893 (ref. ID; 3693)
• Difflugia lebes sphaerica Gauthier-Lievre & Thomas (ref. ID; 2456)
• Difflugia lebes var. elongata Penard (ref. ID; 1923)
  See; Difflugia lebes
• Difflugia lebes var. masurica Schonborn, 1965 (ref. ID; 2109 original paper)
• Difflugia lemani Blanc, 1892 (ref. ID; 2109, 2304, 3693)
• Difflugia lemani var. palustris Chardez, 1956 (ref. ID; 2147, 2151, 2441, 2456)
• Difflugia lenta Ehrenberg, 1871
  See; Sphenoderia lenta (ref. ID; 3693)
• Difflugia leptolepis Ehrenberg, 1871
  See; Quadrula symmetrica (ref. ID; 1316)
• Difflugia levis Ehrenberg, 1845
  See; Euglypha levis (ref. ID; 1332)
• Difflugia ligata Tatem, 1870
  See; Hyalosphenia cuneata (ref. ID; 1316, 3693)
• Difflugia limnetica Levander, 1900 (ref. ID; 3693) or (Levander, 1900) Penard, 1902 (ref. ID; 2028, 2053, 2109, 2330, 2354, 2554) reported year? (ref. ID; 3015, 3496) reported author and year? (ref. ID; 5388)
  Syn; Difflugia lobostoma Leidy var. limnetica Levander, 1900 (ref. ID; 3693)
• Difflugia linearis Penard (ref. ID; 3562) or (Penard) Gauthier-Lievre & Thomas, 1958 (ref. ID; 2027, 2152, 2420, 2460)
• Difflugia lingula Penard, 1911 (ref. ID; 2580)
• Difflugia lismorensis Playfair, 1918 (ref. ID; 1986, 2356)
  Syn; Difflugia crenulata Leidy, 1874 (ref. ID; 1316)
• Difflugia lismorensis quinquelobata Gauthier-Lievre & Thomas, 1958 (ref. ID; 2354)
• Difflugia lithophila Penard, 1902 (ref. ID; 3686) reported year? (ref. ID; 3496) or (Penard, 1902) Gauthier-Lievre & Thomas, 1958 (ref. ID; 2109, 2352)
• Difflugia lithoplita (ref. ID; 2067)
• Difflugia lithoplites Penard, 1902 (ref. ID; 2109, 3693 original paper)
• Difflugia lobostoma Leidy, 1877 (ref. ID; 1316, 2110) or 1879 (ref. ID; 2109) reported year? (ref. ID; 1618, 2067, 2301, 2329, 2330, 2356, 3062, 3595, 3693)
  Syn; Difflugia lobostomata Hempel, 1898 (ref. ID; 1316); Difflugia oblonga Fresenius, 1857 (ref. ID; 1316); Difflugia tricuspis Carter, 1856 (ref. ID; 1316)
• Difflugia lobostoma Leidy var. limnetica Levander, 1900
  See; Difflugia limnetica (ref. ID; 3693)
• Difflugia longicollis Gassowsky, 1936 (ref. ID; 3686) reported year? (ref. ID; 3562)
• Difflugia longum Chardez, 1987 (ref. ID; 2125 original paper)
• Difflugia lucida Penard, 1890 (ref. ID; 1316, 2067, 2099, 2110, 2120, 2329, 2425, 2435, 2441, 4755) reported year? (ref. ID; 3491, 3501, 3693, 5034)
• Difflugia mammillaris Penard (ref. ID; 3693)
• Difflugia manicata Penard, 1902 (ref. ID; 3686, 3693 original paper) reported year? (ref. ID; 1333)
• Difflugia manicata var. langhovdensis Sudzuki, 1964 (ref. ID; 3491, 3536 original paper)
• Difflugia marsupiformis Wallich
  See; Difflugia constricta Ehrenberg (ref. ID; 3693)
• Difflugia masaruzii Van Oye, 1958 (ref. ID; 2235 original paper)
• Difflugia maxilabiosa Chardez (ref. ID; 2125)
• Difflugia mica Frenzel, 1897 (ref. ID; 2067, 2109) reported year? (ref. ID; 3693)
• Difflugia mica var. anulata Schonborn, 1962 (ref. ID; 2051 original paper)
• Difflugia microclaviformis (Kourov) Ogden (ref. ID; 2152)
• Difflugia minuta Rampi, 1950 (ref. ID; 2109, 2110, 2356)
• Difflugia mitriformis Wallich (ref. ID; 2352)
• Difflugia molesta Penard, 1902 (ref. ID; 3693 original paper)
• Difflugia muriformis Gauthier-Lievre & Thomas (ref. ID; 2437)
• Difflugia nana Couteaux, 1976 (ref. ID; 2089 original paper)
• Difflugia nodosa (Leidy) Chardez (ref. ID; 2125, 2147, 2152)
• Difflugia numata Leidy, 1874
  See; Nebela collaris (ref. ID; 1316, 3693)
• Difflugia oblonga (ref. ID; 2067, 2087)
• Difflugia oblonga Ehrenberg, 1838 (ref. ID; 1316, 1923, 2022, 2068, 2077, 2081, 2109, 2235, 2238, 2304, 2329, 2330, 2333, 2356, 2357, 2564, 3173, 3686) reported year? (ref. ID; 1618, 3501, 5034)
  Syn; Difflugia acuminata Leidy, 1879 (ref. ID; 1316); Difflugia pyriformis Forel, 1885 (ref. ID; 1316); Difflugia pyriformis Perty, 1849 (ref. ID; 1316, 1335, 1923) reported year? (ref. ID; 1618)
• Difflugia oblonga (Leidy) (ref. ID; 1308)
• Difflugia oblonga acuminata Ehrenberg (ref. ID; 2304)
• Difflugia oblonga angusticollis Stepanek (ref. ID; 2304)
• Difflugia oblonga brevicolla Cash (ref. ID; 2304)
• Difflugia oblonga curvicollis Varga (ref. ID; 2304), var. curvicollis Varga (ref. ID; 5034 original paper)
• Difflugia oblonga var. atricolor Penard, 1902
  See; Diffluia pyriformis var. atricolor (ref. ID; 2357)
• Difflugia oblonga Ehrenberg var. bryophila Penard, 1902 (ref. ID; 1333, 2304) reported year? (ref. ID; 3595)
  Syn; Difflugia pyriformis var. bryophila Penard, 1902 (ref. ID; 1333)
• Difflugia oblonga var. claviformis (Penard) Cash (ref. ID; 1316, 2067)
  Syn; Difflugia pyriformis Leidy (ref. ID; 1316); Difflugia pyriformis var. claviformis Penard, 1899 (ref. ID; 1316)
• Difflugia oblonga Ehrenberg var. compressa Ehrenberg (ref. ID; 2329)
• Difflugia oblonga var. compressa Leidy (ref. ID; 2236)
• Difflugia oblonga var. cylindrus Thomas, 1953
  See; Difflugia cylindrus (ref. ID; 2151)
• Difflugia oblonga var. elongata Van Oye (ref. ID; 2330 original paper)
• Difflugia oblonga var. gigantea Chardez, 1967
  See; Difflugia gigantea (ref. ID; 2151)
• Difflugia oblonga var. incondita Gauthier-Lievre & Thomas (ref. ID; 2236)
• Difflugia oblonga var. lacustris (Penard) (ref. ID; 3595) or (Penard, 1899) Cash (ref. ID; 1316, 2236)
  Syn; Difflugia pyriformis var. lacustris Penard, 1899 (ref. ID; 1316)
• Difflugia oblonga var. lacustris Penard, 1902 (ref. ID; 2330, 2441, 3173)
• Difflugia oblonga var. longicollis Gassowsky (ref. ID; 2236)
• Difflugia oblonga var. microclaviformis Konrov (ref. ID; 2236) or Kourov, 1925 (ref. ID; 2441)
• Difflugia oblonga var. nodosa Leidy, 1879 (ref. ID; 2109)
• Difflugia oblonga var. parva Thomas, 1954 (ref. ID; 1401, 2109, 2236, 2441, 3173)
  See; Difflugia parva (ref. ID; 2151)
• Difflugia oblonga var. tenuis Penard (ref. ID; 1333, 2236)
  Syn; Difflugia pyriformis var. tenuis Penard, 1890 (ref. ID; 1333)
• Difflugia oblonga var. venusta (Penard, 1902) Cash (ref. ID; 1316, 2236)
  Syn; Difflugia pyriformis var. venusta Penard, 1902 (ref. ID; 1316)
• Difflugia olliformis Lagerheim (ref. ID; 1333)
• Difflugia orbicularis Cash (ref. ID; 1316)
• Difflugia ovalisina Beyens & Chardez, 1994 (ref. ID; 2392 original paper)
• Difflugia oviformis Cash, 1909 (ref. ID; 3686) reported year? (ref. ID; 1316, 2043, 2047, 2110, 2216, 2234, 2329, 2420, 3283, 5034)
• Difflugia papilio Leidy, 1874
  See; Hyalosphenia papilio (ref. ID; 1316)
• Difflugia parva (Thomas) Ogden, 1983 (ref. ID; 2151, 2152)
  Syn; Difflugia oblonga var. parva Thomas, 1954 (ref. ID; 2151); Difflugia pyriformis var. parva (Thomas) Chardez & Decloitre, 1973 (ref. ID; 2151)
• Difflugia pelagica Pejler (ref. ID; 2554 original paper)
• Difflugia peltigeracea Carter
  See; Nebela carinata (ref. ID; 3693), Nebela collaris (ref. ID; 3693)
• Difflugia penardi Cash (ref. ID; 3501)
• Difflugia penardi Hopkinson, 1909 (ref. ID; 1316, 2066, 2067, 2109, 2110, 2330, 2356, 2441, 2564, 3173, 3686)
• Difflugia petricola Cash, 1909 (ref. ID; 2022)
• Difflugia pila Decloitre (ref. ID; 2505 original paper)
• Difflugia pilosa Ehrenberg, 1854
  See; Euglypha ciliata (ref. ID; 1332)
• Difflugia planctonica Minkiewicz, 1900
  See; Hyalosphenia planctonica (ref. ID; 3563)
• Difflugia platystoma Penard
  See; Difflugia constricta Ehrenberg (ref. ID; 3693)
• Difflugia polliciformis Van Oye (ref. ID; 2564 original paper)
• Difflugia prisitis Penard, 1902 (ref. ID; 1316)
  Syn; Difflugia fallax Penard, 1890 (ref. ID; 1316)
• Difflugia pristis Penard, 1902 (ref. ID; 3693 original paper) reported year? (ref. ID; 3501, 5034)
• Difflugia proteiformis Ehrenberg
  See; Difflugia globulosa (ref. ID; 3693)
• Difflugia proteiformis Perty?, 1852
  See; Nebela tincta (ref. ID; 1316)
• Difflugia proteiformis Wallich, 1863
  See; Lesquereusia spiralis (ref. ID; 1316)
• Difflugia proteiformis mitriformis var. spiralis Wallich, 1864
  See; Lesquereusia spiralis (ref. ID; 1316)
• Difflugia proteiformis monstrosa Perty, 1852
  See; Lesquereusia modesta (ref. ID; 1316)
• Difflugia proteiformis var. septifera Wallich, 1863
  See; Lesquereusia spiralis (ref. ID; 1316)
• Difflugia proteiformis var. symmetrica Wallich, 1863
  See; Quadrula symmetrica (ref. ID; 1316, 3693)
• Difflugia pulex Penard, 1902 (ref. ID; 1316, 2067, 2109, 3223, 3693 original paper) reported year? (ref. ID; 3595)
• Difflugia pulex var. cuneata Playfair, 1917 (ref. ID; 2109) or 1918 (ref. ID; 1401)
• Difflugia pyriformella Chardez, 1982 (ref. ID; 2392, 2460 original paper) reported year? (ref. ID; 2027, 2152, 3562)
• Difflugia pyriformis Forel, 1885
  See; Difflugia oblonga (ref. ID; 1316)
• Difflugia pyriformis Perty, 1849 (ref. ID; 890, 2027, 2125, 2147, 2456) or 1852 (ref. ID; 2352, 2357, 3693) reported year? (ref. ID; 3562) reported author and year? (ref. ID; 2770)
  See; Difflugia oblonga (ref. ID; 1316, 1618, 1335, 1923)
• Difflugia pyriformis f. bacillifera Penard (ref. ID; 2352)
  Syn; Difflugia bacillifera Penard, 1902 (ref. ID; 2352)
• Difflugia pyriformis f. compressa Carter (ref. ID; 2352)
  Syn; Difflugia compressa Carter, 1864 (ref. ID; 2352)
• Difflugia pyriformis f. cyphodera Jung, 1942 (ref. ID; 2147, 2352) or Joung (ref. ID; 2357)
• Difflugia pyrifomris f. typica Penard (ref. ID; 2352)
  Syn; Difflugia pyriformis Penard, 1902 (ref. ID; 2352)
• Difflugia pyriformis var. angusticollis (Stepanek, 1963) (ref. ID; 2357)
• Difflugia pyriformis var. antero-cylindrica (Lepsi, 1965) (ref. ID; 2357)
• Difflugia pyriformis var. atricolor Penard, 1902 (ref. ID; 2357, 3693 original paper)
  Syn; Difflugia oblonga var. atricolor (ref. ID; 2357)
• Difflugia pyriformis var. atricolor f. spinulosa Lepsi, 1967 (ref. ID; 2357)
• Difflugia pyriformis var. brevicollis (Gassowsky) (ref. ID; 2357)
• Difflugia pyriformis var. bryophila Penard, 1902 (ref. ID; 2352, 2367, 2592, 3693 original paper)
• Difflugia pyriformis var. caudata (Stepanek, 1952/53) (ref. ID; 2357)
• Difflugia pyriformis var. claviformis Penard, 1902 (ref. ID; 2357) reported year? (ref. ID; 2147, 3693)
• Difflugia pyriformis var. cornuta Leidy, 1879 (ref. ID; 2357)
• Difflugia pyriformis var. crassa (Cash-Hopkinson-Wailes) (Chardez) (ref. ID; 2357)
• Difflugia pyriformis var. curvicollis (Kourov) (ref. ID; 2357)
• Difflugia pyriformis var. cylindrus (Thomas) Chardez & Decloitre, 1973 (ref. ID; 2027, 2357)
  See; Difflugia cylindrus (ref. ID; 2151)
• Difflugia pyriformis var. elongata (Van Oye) Chardez & Decloitre (ref. ID; 2357, 2460)
• Difflugia pyriformis var. frontelata (Lepsi, 1965) (ref. ID; 2357)
• Difflugia pyriformis var. gigantea Leidy, 1879 (ref. ID; 2357)
• Difflugia pyriformis var. heali (Stepanek, 1963) (ref. ID; 2357)
• Difflugia pyriformis var. incondita (Gauthier-Lievre & Thomas) (ref. ID; 2357)
• Difflugia pyriformis var. lacustris Penard, 1902 (ref. ID; 2357, 2367) reported year? (ref. ID; 3693)
• Difflugia pyriformis var. lacustris f. mamrensis (Moraczewsky, 1961) (ref. ID; 2357)
• Difflugia pyriformis var. lata Jung (ref. ID; 2027, 2460) or Joung (ref. ID; 2357)
• Difflugia pyriformis var. longicollis Gassowsky, 1936 (ref. ID; 2357)
• Difflugia pyriformis var. microclaviformis (Kourov) (ref. ID; 2357)
• Difflugia pyriformis var. nodosa Leidy, 1879 (ref. ID; 2357) reported year? (ref. ID; 3693)
• Difflugia pyriformis var. nodosa f. elsteri (Stepanek, 1968) (ref. ID; 2357)
• Difflugia pyriformis var. nodosa f. tricornis (Stepanek, 1963) (ref. ID; 2357)
• Difflugia pyriformis var. parva (Thomas) Chardez & Decloitre, 1973 (ref. ID; 2147, 2357)
  See; Difflugia parva (ref. ID; 2151)
• Difflugia pyriformis var. parva f. leidyi Chardez & Gasper, 1976 (ref. ID; 2150 original paper)
• Difflugia pyriformis var. razmepi Tarnogradsky, 1957 (ref. ID; 2357)
• Difflugia pyriformis var. rocki (Stepanek) (ref. ID; 2357)
• Difflugia pyriformis var. schizocaulis (Stepanek) (ref. ID; 2357)
• Difflugia pyriformis var. stepaneki (Stepanek-Decloitre) (ref. ID; 2357)
• Difflugia pyriformis var. symmetrica Wallich, 1863 (ref. ID; 1335)
  See; Quadrula symmetrica (ref. ID; 1316)
• Difflugia pyriformis var. tenuis Penard, 1890 (ref. ID; 2357)
  See; Difflugia tenuis
• Difflugia pyriformis var. vas Leidy, 1879
  See; Pontigulasia vas (ref. ID; 1316)
• Difflugia pyriformis var. vas bigibbosa Penard, 1899
  See; Pontigulasia compressa (ref. ID; 1316)
• Difflugia pyriformis var. venusta Penard, 1902 (ref. ID; 2147, 2357, 3693 original paper)
  See; Difflugia venusta (ref. ID; 2151)
• Difflugia reticulata Ehrenberg, 1848
  See; Nebela collaris (ref. ID; 1316)
• Difflugia richmondiae Playfair, 1914 (ref. ID; 2109)
• Difflugia rotunda (Chardez) Ogden, 1983 (ref. ID; 2151, 2152)
  Syn; Difflugia globularis var. sphaerica Chardez, 1956 (ref. ID; 2151)
• Difflugia rubescens Penard, 1891 (ref. ID; 1333, 1923, 2067, 2441, 2564, 3686, 4810) reported year? (ref. ID; 3283, 3595, 3693)
  Syn; Difflugia pyriformis Leidy, 1879 (ref. ID; 1333)
• Difflugia rubescens Penard f. major Tarn. (ref. ID; 3501)
• Difflugia rubescens var. brevicollis Schonborn, 1962 (ref. ID; 2051 original paper)
• Difflugia sandbegi Schonborn, 1966 (ref. ID; 2066 original paper)
• Difflugia sarissa L. S. Tai, 1931 (ref. ID; 3299) reported author and year? (ref. ID; 2446)
• Difflugia saxicola Penard (ref. ID; 2392)
• Difflugia scalpellum Penard, 1899 (ref. ID; 2024, 2147, 3173) reported year? (ref. ID; 3693)
• Difflugia schurmanni Van Oye (ref. ID; 3595)
• Difflugia schuurmani Van Oye (ref. ID; 2356, 2564)
• Difflugia semen Ehrenberg, 1871
  See; Assulina seminulum (ref. ID; 1332, 3693)
• Difflugia semiulum Ehrenberg, 1848
  See; Assulina seminulum (ref. ID; 1332, 3693)
• Difflugia septentrionalis Awerintzew, 1906 (ref. ID; 2392) reported year? (ref. ID; 2462)
• Difflugia serbica Ogden & Zivkovic, 1983 (ref. ID; 2151 original paper)
• Difflugia setigera Ehrenberg, 1871
  See; Euglypha acanthophora (ref. ID; 1332)
• Difflugia setigerella acanthophora Ehrenberg, 1871
  See; Euglypha acanthophora (ref. ID; 1332)
• Difflugia setigerella ciliata Ehrenberg, 1871
  See; Euglypha ciliata (ref. ID; 1332)
• Difflugia setigerella pilosa Ehrenberg, 1871
  See; Euglypha ciliata (ref. ID; 1332)
• Difflugia setigerella strigosa Ehrenberg, 1871
  See; Euglypha strigosa (ref. ID; 1332)
• Difflugia smilion Thomas (ref. ID; 2125, 2147, 2239, 2356)
• Difflugia solowetzkii Mereschkowsky, 1879 (ref. ID; 2109)
• Difflugia solowetzkii var. stepaneki Schonborn, 1965 (ref. ID; 2109 original paper)
• Difflugia soudanensis Gauthier-Lievre & Thomas, 1958 (ref. ID; 2151)
• Difflugia sphagni Leidy, 1874
  See; Heleopera sphagni (ref. ID; 1316)
• Difflugia sphincta Jung, 1942 (ref. ID; 2022)
• Difflugia spiralis Ehrenberg, 1840
  See; Lesquereusia spiralis (ref. ID; 1316)
• Difflugia spiralis Fresenius, 1858
  See; Lesquereusia modesta (ref. ID; 1316)
• Difflugia stechlinensis Schonborn, 1962 (ref. ID; 1401, 2051 original paper, 2109)
• Difflugia stechlinensis var. arctica Schonborn, 1966 (ref. ID; 1401, 2066 original paper)
• Difflugia strigosa Ehrenberg, 1871
  See; Euglypha strigosa (ref. ID; 1332, 3693)
• Difflugia submarina Chardez & Thomas, 1980 (ref. ID; 2119 original paper, 3519)
  Syn; Difflugia subterranea f. circularis Chardez, 1971 (ref. ID; 2119)
• Difflugia subterranea Golemanksy, 1970 (ref. ID; 3519)
• Difflugia subterranea f. circularis Chardez, 1971 (ref. ID; 2144 original paper)
  See; Difflugia submarina (ref. ID; 2119)
• Difflugia subterranea var. inflata Decloitre, 1975 (ref. ID; 3519) reported year? (ref. ID; 2517)
• Difflugia sudiformis Schonborn, 1966 (ref. ID; 2066 original paper)
• Difflugia symmetrica Wallich, 1885 (ref. ID; 1316) reported year? (ref. ID; 3693)
  See; Nebela collaris (ref. ID; 3693), Quadrula symmetrica (ref. ID; 1316, 3693)
• Difflugia szczepanskii Schonborn, 1965 (ref. ID; 2109 original paper)
• Difflugia tenuis (Penard, 1890) Chardez (ref. ID; 2460 redescribed paper)
  Syn; Difflugia pyriformis var. tenuis Penard, 1890 (ref. ID; 2460)
• Difflugia tracta Schonborn, 1966 (ref. ID; 2066 original paper)
• Difflugia triangulata Lang, 1865
  See; Nebela triangulata (ref. ID; 1316)
• Difflugia tuberculata (Wallich, 1864) (ref. ID; 3686) reported year? (ref. ID; 3693), (Wallich, 1864) Archer, 1867 (ref. ID; 1316, 1923, 2147, 3761) reported year? (ref. ID; 3595) or Archer, 1897 (ref. ID; 2109) reported year? (ref. ID; 2329, 2330, 3062)
  See; Nebela tuberculata (ref. ID; 3761)
  Syn; Difflugia lobostoma Leidy, 1879 (ref. ID; 1316) reported year? (ref. ID; 3693); Difflugia lobostoma var. tuberculata Minkiewicz, 1900 (ref. ID; 1316); Difflugia proteiformis globularis var. tuberculata Wallich, 1864 (ref. ID; 1316)
• Difflugia tuberculata var. minor Wailes (ref. ID; 1333, 3595)
• Difflugia umbilicata (Penard) Chardez (ref. ID; 2152)
• Difflugia urceolata (ref. ID; 2067)
• Difflugia urceolata Carter, 1864 (ref. ID; 1316, 1923, 2090, 2109, 2125, 2147, 2150, 2330, 2352, 2356, 3686) reported year? (ref. ID; 1618, 3595, 3693)
  Syn; Difflugia lageniformis Butschli, 1880 (ref. ID; 1316) or Wallich (ref. ID; 3693); Difflugia proteiformis mitriformis var. lageniformis Wallich, 1864 (ref. ID; 1316)
• Difflugia urceolata France, 1897
  See; Pseudodifflugia gracilis (ref. ID; 1332)
• Difflugia urceolata (Leidy) (ref. ID; 1308)
• Difflugia urceolata f. suburceola Chardez & Gasper, 1976 (ref. ID; 2150 original paper), var. suburceola Chardez & Gasper (ref. ID; 2147)
• Difflugia urceolata var. lebes Penard, 1893
  See; Difflugia lebes Penard (ref. ID; 3693)
• Difflugia urceolata var. minor Deflandre (ref. ID; 2147, 2152)
• Difflugia urceolata var. olla Leidy (ref. ID; 1923, 2068) reported author and year? (ref. ID; 3693)
  See; Difflugia urceolata
• Difflugia urceolata var. olla Penard (ref. ID; 2147, 2152, 3693)
• Difflugia urceolata var. sphaerica Playfair (ref. ID; 2147)
• Difflugia varians Penard, 1902 (ref. ID; 2109, 3693 original paper)
• Difflugia vas Leidy, 1874
  See; Nebela vas (ref. ID; 4643), Pontigulasia vas (ref. ID; 1316)
• Difflugia venusta (Penard) Ogden, 1983 (ref. ID; 2151)
  Syn; Difflugia pyriformis var. venusta Penard, 1902 (ref. ID; 2151)
• Difflugia ventricosa Deflandre, 1926 (ref. ID; 2453)
• Difflugia viscidula Penard, 1902 (ref. ID; 2109, 2125, 2151, 2152, 3686, 3693 original paper)