In synonymy:
Chocorua Crosby & Bishop, 1933 = Diplocephalus Bertkau, 1883 (Hackman, 1954: 28)
Hemistajus Schenkel, 1934 = Diplocephalus Bertkau, 1883 (Thaler, 1970: 256, by transfer of the type species)
Plaesiocraerus Simon, 1884 = Diplocephalus Bertkau, 1883 (Denis, 1949a: 140)
Prosoponcus Simon, 1884 = Diplocephalus Bertkau, 1883 (Simon, 1894a: 656)
Streptosphaenus Simon, 1926 = Diplocephalus Bertkau, 1883 (Denis, 1949a: 140)

type Erigone foraminifera O. Pickard-Cambridge, 1875; gender masculine; syn. of Diplocephalus cristatus (Blackwall, 1833)

N.B.: considered a senior synonym of Prosoponcus Simon, 1884a: 569 [urn:lsid:nmbe.ch:spidergen:05362] (type Walckenaeria cristatus Blackwall, 1833) by Simon, 1894a: 656; considered a senior synonym of Plaesiocraerus Simon, 1884a: 745 [urn:lsid:nmbe.ch:spidergen:05364] (type Walckenaera latifrons O. Pickard-Cambridge, 1863) (itself not a senior synonym of Monocephalus Smith, 1906), of Streptosphaenus Simon, 1926: 384, 497 [urn:lsid:nmbe.ch:spidergen:05365] (type Diplocephalus adjacens O. Pickard-Cambridge, 1903 = D. connatus Bertkau, 1889) by Denis, 1949a: 140, of Chocorua Crosby & Bishop, 1933b: 164 [urn:lsid:nmbe.ch:spidergen:05363] (type Lophocarenum cuneatum Emerton, 1909) by Hackman, 1954: 28 and of Hemistajus Schenkel, 1934: 90 [urn:lsid:nmbe.ch:spidergen:06060] (type Diplocephalus rostratus Schenkel, 1934) by Thaler, 1970: 256 (by transfer of the type species; Hemistajus was described as subgenus of Diplocephalus and elevated to genus by Schmölzer, in Janetschek, 1956: 479); for illustrations of the modified male carapace and a phylogenetic tree of six European species, see Schaible & Gack, 1987; a generic re-organisation of the Savignia group (includes Araeoncus, Dicymbium, Diplocephalus, Erigonella, Glyphesis) is pending (Frick, Nentwig & Kropf, 2010); the proposed synonymy with Savignia Blackwall, 1833 by Breitling, 2021: 22 is not followed here as it is based mainly on COI (see FAQ 7).

Transferred to other genera:
Diplocephalus antepenultimus (O. Pickard-Cambridge, 1882) -- see Tapinocyboides
Diplocephalus buddebergi (Bösenberg, 1899) -- see Thyreosthenius
Diplocephalus cottoni La Touche, 1946 -- see Glyphesis
Diplocephalus curvicervix Denis, 1964 -- see Typhochrestus
Diplocephalus diphyus Heimer, 1987 -- see Dactylopisthes
Diplocephalus fuscipes (Blackwall, 1836) -- see Monocephalus
Diplocephalus fuscipes castaneipes (Simon, 1884) -- see Monocephalus
Diplocephalus leberti (Roewer, 1942) -- see Caracladus
Diplocephalus montanus (Emerton, 1882) -- see Walckenaeria
Diplocephalus pulicarius (Thorell, 1875) -- see Microctenonyx
Diplocephalus pygmaeus (Menge, 1869) -- see Tapinocyboides
Diplocephalus saganus Bösenberg & Strand, 1906 -- see Diplocephaloides
Diplocephalus semiglobosus (Westring, 1861) -- see Entelecara
Diplocephalus tauricus (Thorell, 1875) -- see Styloctetor
Diplocephalus tenellus (Bösenberg, 1899) -- see Tapinocyba
Diplocephalus wamotsus Chamberlin, 1919 -- see Hybauchenidium
Diplocephalus yasudai Saito, 1986 -- see Savignia

In synonymy:
Diplocephalus adjacens O. Pickard-Cambridge, 1904 = Diplocephalus connatus Bertkau, 1889 (Wiehle, 1960a: 496).
Diplocephalus alpinus strandi Kolosváry, 1937 = Diplocephalus alpinus (O. Pickard-Cambridge, 1873) (Breitling et al., 2016b: 58).
Diplocephalus arvernus Denis, 1948 = Diplocephalus cristatus (Blackwall, 1833) (Bosmans & Oger, 2018: 54).
Diplocephalus bicephalus (Simon, 1884) = Diplocephalus cristatus (Blackwall, 1833) (Bosmans & Oger, 2018: 54).
Diplocephalus bicornis (Wider, 1834, T from Lophomma) = Diplocephalus cristatus (Blackwall, 1833) (Thorell, 1871a: 108, sub Erigone).
Diplocephalus bihamatus (Menge, 1868, T from Lophocarenum) = Diplocephalus latifrons (O. Pickard-Cambridge, 1863) (Thorell, 1871a: 107, sub Erigone).
Diplocephalus brunneus (Bösenberg, 1902, T from Araeoncus) = Diplocephalus permixtus (O. Pickard-Cambridge, 1871) (Tullgren, 1955: 328).
Diplocephalus caespitum (C. L. Koch, 1841, T from Micryphantes) = Diplocephalus cristatus (Blackwall, 1833) (Thorell, 1871a: 108, sub Erigone).
Diplocephalus connectens Kulczyński, 1894 = Diplocephalus alpinus (O. Pickard-Cambridge, 1873) (Thaler, 1995b: D479, sub D. connectens).
Diplocephalus cristatus angusticeps Holm, 1973 = Diplocephalus cristatus (Blackwall, 1833) (Tanasevitch, 2011c: 138).
Diplocephalus cuneatus (Emerton, 1909) = Diplocephalus subrostratus (O. Pickard-Cambridge, 1873) (Eskov, 1988c: 23).
Diplocephalus dimidiatus (Denis, 1945) = Diplocephalus graecus (O. Pickard-Cambridge, 1873) (Denis, 1964c: 63).
Diplocephalus eborodunensis (O. Pickard-Cambridge, 1875) = Diplocephalus helleri (L. Koch, 1869) (Simon, 1926: 497, sub Plaesiocraerus).
Diplocephalus foraminifer (O. Pickard-Cambridge, 1875) = Diplocephalus cristatus (Blackwall, 1833) (Bosmans & Oger, 2018: 54).
Diplocephalus foraminifer thyrsiger (Simon, 1884) = Diplocephalus cristatus (Blackwall, 1833) (Bosmans & Oger, 2018: 54).
Diplocephalus incertus (L. Koch, 1879, T from Erigone) = Diplocephalus barbiger (Roewer, 1955) (Holm, 1970: 191, sub D. barbatus).
Diplocephalus maculifrons Kulczyński, 1926 = Diplocephalus subrostratus (O. Pickard-Cambridge, 1873) (Eskov, 1988c: 23).
Diplocephalus meticulosus (Simon, 1918, T from Entelecara) = Diplocephalus picinus (Blackwall, 1841) (Denis, 1949a: 136).
Diplocephalus morum (O. Pickard-Cambridge, 1894, T from Gongylidium) = Diplocephalus picinus (Blackwall, 1841) (O. Pickard-Cambridge, 1911b: 53).
Diplocephalus nuncius (Simon, 1882, T from Erigone) = Diplocephalus graecus (O. Pickard-Cambridge, 1873) (Simon, 1926: 512, sub Entelecara).
Diplocephalus obtusus Denis, 1952 = Diplocephalus helleri (L. Koch, 1869) (Georgescu, 1969a: 204).
Diplocephalus opacithorax (Simon, 1884) = Diplocephalus latifrons (O. Pickard-Cambridge, 1863) (Simon, 1926: 380, sub Plaesiocraerus).
Diplocephalus picinus humiliceps (Denis, 1945) = Diplocephalus picinus (Blackwall, 1841) (Wiehle, 1960a: 515).
Diplocephalus rectilobus (Simon, 1884) = Diplocephalus cristatus (Blackwall, 1833) (Bosmans & Oger, 2018: 54).
Diplocephalus sabulicola Bosmans, 1996 = Diplocephalus mystacinus (Simon, 1884) (Bosmans, 2002: 22).
Diplocephalus spinosus Hull, 1901 = Diplocephalus permixtus (O. Pickard-Cambridge, 1871) (Jackson, 1907b: 404).
Diplocephalus tatricus (Kulczyński, 1882, T from Erigone) = Diplocephalus helleri (L. Koch, 1869) (Simon, 1884a: 755, sub Plaesiocraerus).

Homonyms replaced:
Diplocephalus barbatus (L. Koch, 1879) -- see Diplocephalus barbiger (see Roewer, 1955c)
Diplocephalus montanus Tanasevitch, 1989 -- see Diplocephalus montaneus

Nomina dubia:
Diplocephalus alpinus subrufus Roșca, 1935: 245, f. 5-6 (mf, Romania) -- Fedoriak, Voloshyn & Moscaliuc, 2016: 86.
Diplocephalus coniceps Strand, 1906b: 616 (m, Somalia) -- Scharff, 1990b: 144.
Diplocephalus fallaciosus (Bertkau, in Förster & Bertkau, 1883: 229, pl. 3, f. 2, m, Germany, originally in Lophocarenum) -- Wiehle, 1960a: 514.
Diplocephalus pullinus Simon, 1918b: 153 (m, France) -- Lecigne et al., 2022: 14.

Diplocephalus algericus Bosmans, 1996: 142, f. 59-67 (Dmf).

Erigone alpina O. Pickard-Cambridge, 1873a: 767, pl. 66, f. 24 (Dm).
Diplocephalus connectens Kulczyński, in Chyzer & Kulczyński, 1894: 109, pl. 4, f. 24 (Dmf) [urn:lsid:nmbe.ch:spidersp:060652].
Plaesiocraerus alpinus Simon, 1926: 496.
Plaesiocraerus connectens Simon, 1926: 496.
Diplocephalus annectens strandi Kolosváry, 1937a: 401 (Dm) [urn:lsid:nmbe.ch:spidersp:010039].
Diplocephalus connectens Niculescu-Burlacu, 1968: 92, f. 6 (f).
Diplocephalus connectens Thaler, 1995b: D479 (S of Diplocephalus alpinus, used the younger name without evidence).
Diplocephalus connectens Pesarini, 1996: 416, f. 13-14, 20 (mf).
Diplocephalus alpinus Breitling et al., 2016b: 58 (S of Diplocephalus alpinus strandi).

Diplocephalus altimontanus Deltshev, 1984: 91, f. 1-9 (Dmf).

Diplocephalus arnoi Isaia, 2005a: 1, f. 2-8 (Dmf).
Diplocephalus arnoi Frick & Isaia, 2012: 68, f. 11-13 (mf).

Erigone barbata L. Koch, 1879c: 60, pl. 2, f. 13-13b (Dmf; preoccupied by Thorell, 1875, see Porrhomma pygmaeum) [urn:lsid:nmbe.ch:spidersp:060660].
Erigone incerta L. Koch, 1879c: 52, pl. 2, f. 6-6a (Df; suppressed for lack of usage) [urn:lsid:nmbe.ch:spidersp:060655].
Typhochraestus barbatus Strand, 1906a: 444.
Diplocephalus barbatus Kulczyński, 1908b: 11, pl. 1, f. 14-17, 21 (mf).
Savignia barbata Dahl, 1928: 18, f. 27-28 (f).
Diplocephalus (Hemistajus) barbatus Schenkel, 1934: 90.
Savignia barbigera Roewer, 1955b: 1495 (replacement name for Erigone barbata L. Koch, 1879).
Erigone incerta Roewer, 1955c: 1498 (nicht zu deuten = nomen dubium).
Savignia barbata Leech, 1966: 190, f. 58-61 (mf).
Diplocephalus barbatus Holm, 1967: 28, f. 32-36 (mf, T from Savignia).
Diplocephalus barbatus Holm, 1970: 191, f. 4-6 (m, S of Erigone incerta).
Diplocephalus barbatus Eskov, 1988c: 16, f. 7-11 (mf).
Diplocephalus barbiger Marusik, 2015: 686, f. 11C-D (f).

Diplocephalus bicurvatus Bösenberg & Strand, 1906: 160, pl. 12, f. 272 (Dmf).
Diplocephalus bicurvatus Ono, Matsuda & Saito, 2009: 277, f. 230-234 (m).

Diplocephalus bifurcatus Tanasevitch, 1989a: 131, f. 131-136 (Dm).

Diplocephalus caecus Denis, 1952b: 47, f. 42-47 (Dm).
Diplocephalus caecus Heimer & Nentwig, 1991: 144, f. 403 (m).

Diplocephalus caucasicus Tanasevitch, 1987a: 346, f. 95-105 (Dmf).
Diplocephalus caucasicus Tanasevitch, 1990: 48, f. 17.5-7, 18.3-4, 28.10-11 (mf).

Diplocephalus connatus Bertkau, 1889: 74 (Dm).
Diplocephalus connatus Bösenberg, 1902: 191, pl. 17, f. 263 (m, Df).
Diplocephalus adjacens O. Pickard-Cambridge, 1904a: 165, pl. A, f. 8 (Dmf) [urn:lsid:nmbe.ch:spidersp:060650].
Streptosphaenus adjacens Simon, 1926: 384, 497, f. 684-685 (Dmf).
Diplocephalus adjacens Locket & Millidge, 1953: 294, f. 177C-D, H, 179F (mf).
Diplocephalus connatus Wiehle, 1960a: 496, f. 916-925 (mf, S of Diplocephalus adjacens).
Diplocephalus connatus Locket, Millidge & Merrett, 1974: 98 (S of Diplocephalus adjacens confirmed).
Diplocephalus connatus Roberts, 1987: 86, f. 37b, 39k (mf).
Diplocephalus connatus Schaible & Gack, 1987: 179, f. 7 (m prosoma).
Diplocephalus connatus Heimer & Nentwig, 1991: 140, f. 393 (mf).

Diplocephalus jacksonii O. Pickard-Cambridge, 1904a: 166, pl. A, f. 9-9a (Dmf).
Diplocephalus jacksoni Locket & Millidge, 1953: 295, f. 177F.
Diplocephalus connatus jacksoni Roberts, 1987: 86, f. 391 (downgraded to "form").

Prosoponcus crassiloba Simon, 1884a: 575, f. 390 (Dm).
Diplocephalus crassiloba Simon, 1926: 378, 495, f. 675-677 (m, Df).
Diplocephalus crassilobus Millidge, 1979: 324, f. 50-59 (mf).
Diplocephalus foraminifer Maurer & Hänggi, 1989: 180, f. 8-11 (m; misidentified per Hänggi & Stäubli, 2012: 61).
Diplocephalus crassiloba Pesarini, 1996: 417, f. 15-17, 21 (mf).
Diplocephalus crassilobus Gnelitsa, 2006a: 373, f. 3a-b (m).
Diplocephalus crassilobus Danisman et al., 2011a: 142, f. 1-4, 5a-b (m).

Walckenaeria cristatus Blackwall, 1833: 107 (Dmf).
Theridion bicorne Wider, 1834: 220, pl. 14, f. 12 (Dmf) [urn:lsid:nmbe.ch:spidersp:060692].
Walckenaeria cristatus Blackwall, 1834b: 317, pl. 2, f. 7-10 (mf).
Argus bicornis Walckenaer, 1841: 365.
Micryphantes caespitum C. L. Koch, 1841a: vol. 8: 104, f. 673-674 (Dmf) [urn:lsid:nmbe.ch:spidersp:060693].
Erigone bicornis Westring, 1851: 41.
Melicertus bicornis Simon, 1864: 196.
Walckenaera cristatus Blackwall, 1864a: 309, pl. 21, f. 224 (mf).
Lophomma bicorne Menge, 1868: 212, pl. 42, f. 111 (mf).
Erigone cristata Thorell, 1871a: 108 (S of Lophomma bicorne and Micryphantes caespitum).
Erigone foraminifera O. Pickard-Cambridge, 1875b: 207, pl. 28, f. 15 (Dm) [urn:lsid:nmbe.ch:spidersp:010056].
Lophomma cristata Emerton, 1882: 44, pl. 10, f. 1 (mf).
Prosoponcus bicephalus Simon, 1884a: 575, f. 388-389 (Dm) [urn:lsid:nmbe.ch:spidersp:010044].
Prosoponcus cristatus Simon, 1884a: 570, f. 380-381 (mf).
Prosoponcus foraminifer Simon, 1884a: 572, f. 382-383 (m).
Prosoponcus thyrsiger Simon, 1884a: 574, f. 386-387 (Dm) [urn:lsid:nmbe.ch:spidersp:010057].
Prosoponcus rectiloba Simon, 1884a: 573, f. 384-385 (Dm) [urn:lsid:nmbe.ch:spidersp:010075].
Diplocephalus cristatus Chyzer & Kulczyński, 1894: 109, pl. 4, f. 22 (mf).
Diplocephalus crassilobus Chyzer & Kulczyński, 1894: 109, pl. 4, f. 29 (Dm).
Diplocephalus bicephalus Simon, 1894a: 613, f. 653-654 (m).
Diplocephalus cristatus Becker, 1896: 116, pl. 11, f. 5 (mf).
Diplocephalus cristatus Smith, 1901a: 360, p. 359: f. 1m, 2g (m).
Diplocephalus cristatus Bösenberg, 1902: 191, pl. 17, f. 264 (mf).
Lophomma cristatus Banks, 1916: 73, pl. 11, f. 29 (f).
Diplocephalus bicephalus Simon, 1926: 378, 495, f. 672-674 (m, Df).
Diplocephalus foraminifer Simon, 1926: 377, 495, f. 667-668 (m).
Diplocephalus foraminifer thyrsiger Simon, 1926: 378, 495, f. 669-671 (m, Df).
Diplocephalus rectilobus Simon, 1926: 377.
Diplocephalus cristatus Bishop & Crosby, 1935c: 239, pl. 20, f. 42-43 (mf).
Diplocephalus cristatus Kaston, 1948: 170, f. 457, 482-483 (m).
Diplocephalus arvernus Denis, 1948b: 238, f. 1-8 (Dmf) [urn:lsid:nmbe.ch:spidersp:010042].
Diplocephalus cristatus Locket & Millidge, 1953: 291, f. 174D, 176D-F (mf).
Diplocephalus cristatus Tullgren, 1955: 324, f. 28a-c (f).
Diplocephalus cristatus Brændegaard, 1958: 52, f. 52-53 (mf).
Diplocephalus cristatus Wiehle, 1960a: 501, f. 926-934 (mf).
Diplocephalus cristatus Merrett, 1963b: 401, f. 66A-E (m).
Diplocephalus cristatus Wiehle, 1967b: 187, f. 12-14 (f).
Diplocephalus cristatus Georgescu, 1969a: 206, f. 3-4, 9-10, 13 (f).
Diplocephalus cristatus foraminifer Georgescu, 1969a: 207, f. 5-8, 11-13 (f, reduced to "groupe de formes").
Diplocephalus foraminifer Denis, 1970: 380 (reduction to subspecies rejected).
Diplocephalus cristatus Tystshenko, 1971: 259, f. 771 (f).
Diplocephalus cristatus Miller, 1971: 280, pl. LIX, f. 19-21 (mf).
Diplocephalus cristatus Holm, 1973: 81, f. 25-26, 28 (f).
Diplocephalus cristatus angusticeps Holm, 1973: 81, f. 23-24, 27 (Dmf) [urn:lsid:nmbe.ch:spidersp:010053].
Diplocephalus cristatus foraminifer Georgescu, 1973b: 259, f. 13 (m).
Diplocephalus cfr. cristatus Brignoli, 1975c: 27, f. 29-30 (m).
Diplocephalus cristatus Palmgren, 1976: 53, f. 16.17-19 (mf).
Diplocephalus cristatus Millidge, 1977: 32, f. 126 (m).
Diplocephalus cristatus Millidge, 1980a: 101, f. 6-7 (m).
Diplocephalus cristatus Millidge, 1984b: 250, f. 103, 106 (f).
Diplocephalus foraminifer Deltshev, 1985a: 361, f. 6-10 (mf).
Diplocephalus cristatus Millidge, 1986: 58, f. 4.
Diplocephalus cristatus Bürgis, 1986a: 354, f. 2 (m).
Diplocephalus cristatus Roberts, 1987: 84, f. 36d, 39g (mf).
Diplocephalus cristatus Schaible & Gack, 1987: 173, f. 1, 7 (m prosoma).
Diplocephalus cristatus Millidge, 1988a: 61, f. 290-292, 296, 299, 307 (mf).
Diplocephalus cristatus Heimer & Nentwig, 1991: 140, f. 396 (mf).
Diplocephalus cristatus Agnarsson, 1996: 97, f. 95A-D (mf).
Diplocephalus cristatus Hormiga, 2000: 33, f. 6A-I, pl. 19A-F, 20A-F, 21A-D, 79D (mf).
Diplocephalus cristatus Paquin & Dupérré, 2003: 98, f. 910-913 (mf).
Diplocephalus cristatus Paquin, Vink & Dupérré, 2010: 56, f. 31.3-6 (mf).
Diplocephalus cristatus Tanasevitch, 2011c: 138 (S of Diplocephalus cristatus angusticeps).
Diplocephalus cristatus Lavery & Snazell, 2013: 58, f. 63-67 (mf).
Diplocephalus cristatus Bosmans & Oger, 2018: 54, f. 1a-o, 2a-f (mf, S of Diplocephalus arvernus, D. foraminifer (downgraded to morph), D. foraminifer thyrsiger, D. rectilobus (all morph foraminifer) and of D. bicephalus (morph cristatus)).
Diplocephalus cristatus Hänggi & Gloor, 2020: 93, f. 8 (m habitus).

Diplocephalus culminicola Simon, 1884a: 875, f. 807-808 (Dm).
Streptosphaenus culminicola Simon, 1926: 385, 498.
Diplocephalus culminicola Denis, 1953a: 94, f. 5-7 (Df, belongs to another species of an undefined genus after Tanasevitch, 2017c: 65).
Diplocephalus culminicola Tanasevitch, 2017c: 64, f. 9 (m, very similar to Dactylopisthes khatipara).

Diplocephalus dentatus Tullgren, 1955: 329, f. 32a-b (Df).
Diplocephalus dentatus Miller, 1959: 54, f. 28-38 (f, Dm).
Diplocephalus dentatus Casemir, 1960: 255, pl. I, f. 1-10, pl. II, f. 1-9 (mf).
Diplocephalus dentatus Wiehle, 1960a: 611, f. 1142-1147 (mf).
Diplocephalus dentatus Miller, 1971: 281, pl. LX, f. 14-17 (mf).
Diplocephalus dentatus Millidge, 1977: 34, f. 129 (m).
Diplocephalus dentatus Schaible & Gack, 1987: 179, f. 7 (m prosoma).
Diplocephalus dentatus Heimer & Nentwig, 1991: 142, f. 397 (mf).
Diplocephalus dentatus Thaler, 1991a: 166, f. 1-3 (mf).

Erigone graeca O. Pickard-Cambridge, 1873a: 755, pl. 65, f. 10 (Dm).
Erigone nuncia Simon, 1882d: 244 (Dm) [urn:lsid:nmbe.ch:spidersp:061182].
Entelecara graeca Simon, 1884a: 334.
Erigone nuncia Simon, 1884a: 625, f. 442-445 (m, Df).
Tapinocyba graeca Simon, 1884a: 787.
Entelecara graeca Simon, 1926: 424, 426, 512, f. 757 (f, S of Erigone nuncia).
Plaesiocraerus graecus Denis, 1945c: 205, f. 2-4 (mf, T from Entelecara).
Plaesiocraerus dimidiatus Denis, 1945c: 206, f. 5-6 (Df) [urn:lsid:nmbe.ch:spidersp:060654].
Diplocephalus graecus Denis, 1964c: 63 (S of Diplocephalus dimidiatus).
Diplocephalus graecus Denis, 1968d: 156, f. 19-25 (mf).
Diplocephalus graecus Thaler, 1977: 558, f. 6-7 (f).
Diplocephalus graecus Bosmans, 1996: 136, f. 43-50 (mf).
Diplocephalus graecus Bonte et al., 2002: 132, f. 1A-C (mf).
Diplocephalus graecus Dawson, Merrett & Russell-Smith, 2011: 211, f. 1-11 (mf).
Diplocephalus graecus Lecigne, 2016d: 14, f. 4A-D (mf).
Diplocephalus graecus Danışman & Coşar, 2022c: 76, f. 1A-D, 2A-E, 3 (m).
Diplocephalus graecus Bach, Zäpernick & Stratemann, 2023: 14, f. 2a-f (mf).
Diplocephalus graecus Rehfeldt & Cassar, 2024: 26, f. 18a-d (f).

Diplocephalus gravidus Strand, in Bösenberg & Strand, 1906: 161 (Df).
Diplocephalus gravidus Ono, Matsuda & Saito, 2009: 277, f. 235-238 (f).

Diplocephalus guidoi Frick & Isaia, 2012: 65, f. 1-10 (Dmf).

Erigone helleri L. Koch, 1869: 195 (Dmf).
Erigone eborodunensis O. Pickard-Cambridge, 1875b: 204, pl. 28, f. 13 (Dm) [urn:lsid:nmbe.ch:spidersp:061183].
Erigone tatrica Kulczyński, 1882b: 28, pl. 3, f. 17 (Dmf) [urn:lsid:nmbe.ch:spidersp:061184].
Plaesiocraerus eborodunensis Simon, 1884a: 753, f. 641-645 (mf, S of Erigone tatrica).
Plaesiocraerus helleri Simon, 1884a: 755, f. 646 (m).
Diplocephalus helleri Chyzer & Kulczyński, 1894: 111, pl. 4, f. 26 (mf).
Diplocephalus eborodunensis Lessert, 1905b: 629.
Diplocephalus eborodunensis Lessert, 1910b: 149, f. 88-91 (mf).
Plaesiocraerus helleri Simon, 1926: 380, 382, 497 (S of Diplocephalus eborodunensis).
Diplocephalus obtusus Denis, 1952b: 4, f. 5-16 (Dmf) [urn:lsid:nmbe.ch:spidersp:060658].
Diplocephalus helleri Wiehle, 1967a: 7, f. 25-29 (m; f see Araeoncus anguineus).
Diplocephalus helleri Georgescu, 1969a: 204 (S of Diplocephalus obtusus).
Diplocephalus helleri Miller, 1971: 282, pl. LX, f. 8-10 (mf).
Diplocephalus helleri Wunderlich, 1973d: 395, f. 4-5 (f).
Diplocephalus helleri Millidge, 1977: 34, f. 131 (m).
Diplocephalus helleri Thaler, 1978a: 185, f. 10 (f).
Diplocephalus helleri Heimer & Nentwig, 1991: 142, f. 400.1-2, 5 (m; f see Araeoncus anguineus).
Diplocephalus helleri Pesarini, 1996: 417, f. 18-19, 22 (mf).
Diplocephalus helleri Sacher & Bellstedt, 1998: 91, f. 8 (f).

Diplocephalus hispidulus Saito & Ono, 2001: 42, f. 86-91 (Dmf).
Diplocephalus hispidulus Ono, Matsuda & Saito, 2009: 277, f. 239-243 (mf).
Diplocephalus hispidulus Serita, 2021e: 276, f. 1s-t (f).
Diplocephalus hispidulus Ohchi, 2022a: 174, f. 5-6 (m).

Diplocephalus hungaricus Kulczyński, 1915: 923, pl. 66, f. 36-42 (Dmf).
Diplocephalus hungaricus Gnelitsa, 2006a: 373, f. 3c-e (m).

Diplocephalus inanis Tanasevitch, 2014c: 278, f. 1-8 (Dmf).

Diplocephalus komposchi Milasowszky, Bauder & Hepner, 2017: 297, f. 1-12 (Dmf).

Thaumatoncus lancearius Simon, 1884a: 582 (Dm).
Trachelocamptus lancearius Reimoser, 1919: 69.
Diplocephalus lancearius Bosmans, 2002: 22, f. 67-72 (m, Df, T from Trachelocamptus = Acartauchenius).

Walckenaera latifrons O. Pickard-Cambridge, 1863: 8594 (Dmf).
Lophocarenum bihamatum Menge, 1868: 200, pl. 39, f. 97 (Dmf) [urn:lsid:nmbe.ch:spidersp:061185].
Erigone latifrons Thorell, 1871a: 107 (S of Lophocarenum bihamatum).
Walckenaera latifrons O. Pickard-Cambridge, 1873b: 454, pl. 35, f. 31 (mf).
Erigone latifrons Dahl, 1883: 48.
Plaesiocraerus alpinus Simon, 1884a: 760, f. 657-659 (mf; misidentified per Simon, 1926: 496).
Plaesiocraerus latifrons Simon, 1884a: 762, f. 660-662 (mf).
Plaesiocraerus opacithorax Simon, 1884a: 764 (Dm) [urn:lsid:nmbe.ch:spidersp:061186].
Lophocarenum latifrons Dahl, 1886: 85.
Diplocephalus latifrons Chyzer & Kulczyński, 1894: 111, pl. 4, f. 27 (mf).
Plaesiocraerus latifrons Becker, 1896: 143, pl. 12, f. 1 (mf).
Diplocephalus latifrons Smith, 1901a: 360, p. 359: f. 2j (m).
Erigonella latifrons Dahl, 1901c: 262.
Diplocephalus latifrons Bösenberg, 1902: 193, pl. 17, f. 266 (mf).
Plaesiocraerus latifrons Simon, 1926: 380, 495, f. 678-679 (mf, S of Plaesiocraerus opacithorax).
Plaesiocraerus latifrons Hackman, 1952b: 77, f. 10a-b, 19 (mf).
Diplocephalus latifrons Locket & Millidge, 1953: 293, f. 177A-B, E, G, 179E (mf).
Diplocephalus latifrons Tullgren, 1955: 327, f. 30a-e (mf).
Diplocephalus latifrons Wiehle, 1960a: 510, f. 942-950 (mf).
Diplocephalus latifrons Miller, 1971: 281, pl. LX, f. 11-13 (mf).
Diplocephalus cfr. latifrons Brignoli, 1975c: 27, f. 31-33 (mf).
Diplocephalus latifrons Palmgren, 1976: 54, f. 16.13-16 (mf).
Diplocephalus latifrons Millidge, 1977: 34, f. 134 (m).
Diplocephalus latifrons Roberts, 1987: 86, f. 37a, 39i (mf).
Diplocephalus latifrons Schaible & Gack, 1987: 175, f. 3, 6-7 (m prosoma).
Diplocephalus latifrons Höfer, 1989: 186, pl. 5a (m).
Diplocephalus latifrons Tanasevitch, 1990: 111, f. 22.25, 24.43, 28.13 (mf).
Diplocephalus latifrons Heimer & Nentwig, 1991: 140, f. 395 (mf).
Diplocephalus latifrons Frick, Nentwig & Kropf, 2010: 309, Suppl. pl. 6A-O (mf).

Plaesiocraerus longicarpus Simon, 1884a: 749, f. 634-637 (Dmf).
Plaesiocraerus longicarpus Simon, 1926: 379, 382, 497, 5. 681 (mf).
Diplocephalus longicarpus Thaler, 1972a: 34, f. 25-29, 33 (m).

Erigone lusisca Simon, 1872a: 219, pl. 12, f. 1-5 (Dmf).
Plaesiocraerus lusiscus Simon, 1884a: 759, f. 653-656 (m).
Plaesiocraerus lusiscus Simon, 1894a: 613, f. 652 (m).
Diplocephalus lusiscus Simon, 1913: 365.
Plaesiocraerus lusiscus Simon, 1926: 381, 384, 496, f. 682 (mf).
Diplocephalus lusiscus Wiehle, 1963c: 240, f. 24-33 (mf).
Diplocephalus lusicus Heimer & Nentwig, 1991: 144, f. 402 (mf).
Diplocephalus lusiscus Fernández-Pérez, Castro & Prieto, 2014: 80, 4-6 (mf).

Diplocephalus machadoi Bosmans & Cardoso, in Bosmans, Cardoso & Crespo, 2010: 14, f. 14-22 (Dmf).
Diplocephalus machadoi Tilly, 2015a: 6, f. 1-2, 3A-D, 4 (m).

Diplocephalus sp. Bosmans, 1996: 144, f. 68-69 (f).
Diplocephalus marijae Bosmans, in Bosmans, Cardoso & Crespo, 2010: 16, f. 23-29 (Dmf).

Diplocephalus marusiki Eskov, 1988c: 18, f. 12-17 (Dmf).

Diplocephalus mirabilis Eskov, 1988c: 18, f. 18-24 (Dmf).
Diplocephalus mirabilis Sha, Gao & Zhu, 1994: 14, f. 1-8 (mf).
Diplocephalus mirabilis Song, Zhu & Chen, 1999: 167, f. 92A-D (mf).
Diplocephalus mirabilis Song & Li, 2010a: 128, f. 6A-E, 7A-H, 8A-B (mf).

Diplocephalus montanus Tanasevitch, 1989a: 131, f. 137-141 (Dmf; preoccupied by Eskov, 1988, see Diplocephalus montanus) [urn:lsid:nmbe.ch:spidersp:055861].
Diplocephalus montaneus Tanasevitch, 1992: 50 (replacement name).

Diplocephalus montanus Eskov, 1988c: 20, f. 25-31 (Dmf).

Thaumatoncus mystacinus Simon, 1884a: 582 (Dm).
Trachelocamptus mystacinus Reimoser, 1919: 69.
Diplocephalus sp. a Thaler, 1977: 558, f. 19-21 (f; here per Bosmans, 1996: 139).
Diplocephalus sabulicolus Bosmans, 1996: 139, f. 51-58 (Dmf) [urn:lsid:nmbe.ch:spidersp:010077].
Diplocephalus mystacinus Bosmans, 2002: 22 (T from Trachelocamptus = Acartauchenius, S of Diplocephalus sabulicola).

Diplocephalus parentalis Song & Li, 2010a: 132, f. 9A-D, 10A-H, 11A-C (Dmf).

Diplocephalus aff. procerus Thaler, 1972a: 34, f. 12-23 (mf).
Diplocephalus pavesii Pesarini, 1996: 417, f. 23-27 (Dmf).

Walckenaera permixta O. Pickard-Cambridge, 1871a: 455, pl. 57, f. 40 (Dmf).
Plaesiocraerus permixtus Simon, 1884a: 756, f. 647-648 (m).
Diplocephalus spinosus Hull, 1901: 365 (Dm) [urn:lsid:nmbe.ch:spidersp:061187].
Diplocephalus permixtus Smith, 1901a: 360, p. 359: f. 1n, 2h (m).
Araeoncus brunneus Bösenberg, 1902: 195, pl. 17, f. 270 (Df) [urn:lsid:nmbe.ch:spidersp:060651].
Diplocephalus permixtus Jackson, 1907b: 404 (S of Diplocephalus spinosus).
Streptosphaenus permixtus Simon, 1926: 385, 497, f. 686-687 (mf).
Streptosphaenus permixtus Brændegaard, 1932: 25, f. 9 (f).
Diplocephalus permixtus Locket & Millidge, 1953: 293, f. 178A-C, 179H (mf).
Diplocephalus permixtus Tullgren, 1955: 328, f. 31a-d (mf, S of Araeoncus brunneus).
Diplocephalus permixtus Wiehle, 1960a: 506, f. 935-941 (mf).
Diplocephalus permixtus Wiehle, 1960c: 479, f. 25 (m).
Diplocephalus permixtus Miller, 1971: 280, pl. LIX, f. 22-23, pl. LX, f. 30 (mf).
Diplocephalus permixtus Waaler, 1971a: 21, f. 10 (f).
Diplocephalus permixtus Palmgren, 1976: 55, f. 16.20-22 (mf).
Diplocephalus permixtus Millidge, 1977: 34, f. 133 (m).
Diplocephalus permixtus Roberts, 1987: 84, f. 36e, 39h (mf).
Diplocephalus permixtus Schaible & Gack, 1987: 179, f. 7 (m prosoma).
Diplocephalus permixtus Heimer & Nentwig, 1991: 140, f. 394 (mf).
Diplocephalus permixtus Millidge, 1993c: 147, f. 39 (f).
Diplocephalus permixtus Agnarsson, 1996: 99, f. 97A-D (mf).

Walckenaera picina Blackwall, 1841a: 640 (Dm).
Argus picinus Walckenaer, 1847a: 507.
Walckenaera picina Blackwall, 1864a: 313, pl. 21, f. 228 (m).
Lophocarenum erythropus Menge, 1868: 203, pl. 40, f. 100 (mf; misidentified per Thorell, 1873: 453).
Walckenaera picina Thorell, 1873: 453.
Walckenaera picina O. Pickard-Cambridge, 1879d: 163 (Df).
Erigone picina Dahl, 1883: 47.
Plaesiocraerus picinus Simon, 1884a: 771, f. 679-682 (mf).
Moebelia picina Dahl, 1886: 92.
Diplocephalus picinus Chyzer & Kulczyński, 1894: 112, pl. 4, f. 28 (mf).
Gongylidium morum O. Pickard-Cambridge, 1894c: 21, pl. 1, f. 2a-d (Df) [urn:lsid:nmbe.ch:spidersp:061188].
Diplocephalus picinus Smith, 1901a: 360, p. 359: f. 2k (m).
Diplocephalus picinus Bösenberg, 1902: 193, pl. 17, f. 267 (mf).
Diplocephalus picinus Hull, 1909: 446, pl. 12, f. 16 (f).
Diplocephalus picinus O. Pickard-Cambridge, 1911b: 53 (S of Gongylidium morum).
Savignia picinus Dahl, 1912b: 609.
Entelecara meticulosa Simon, 1918b: 154 (Dm) [urn:lsid:nmbe.ch:spidersp:060657].
Entelecara meticulosa Simon, 1926: 424, 512, f. 752 (m).
Plaesiocraerus picinus humiliceps Denis, 1945c: 208, f. 8-10 (Dmf) [urn:lsid:nmbe.ch:spidersp:060659].
Plaesiocraerus picinus Miller, 1947: 29, pl. VII, f. 11 (f).
Diplocephalus picinus Denis, 1949a: 136 (S of Entelecara meticulosa).
Diplocephalus picinus humiliceps Denis, 1949a: 140.
Savignia picina Hackman, 1952b: 77, f. 9a-c, 17 (mf).
Diplocephalus picinus Locket & Millidge, 1953: 295, f. 179A-D (mf).
Diplocephalus picinus Tullgren, 1955: 325, f. 29a-b (f).
Entelecara meticulosa Wiehle, 1960a: 370, f. 673-675 (m).
Diplocephalus picinus Wiehle, 1960a: 515, f. 951-960 (mf, S of Diplocephalus picinus humiliceps).
Diplocephalus picinus Merrett, 1963b: 402, f. 67A-C (m).
Diplocephalus picinus Miller, 1971: 281, pl. LX, f. 18-20 (mf).
Diplocephalus picinus Waaler, 1971a: 22, f. 11-12 (mf).
Diplocephalus picinus Palmgren, 1976: 55, f. 16.9-12 (mf).
Diplocephalus picinus Millidge, 1977: 32, f. 122 (m).
Diplocephalus picinus Roberts, 1987: 86, f. 37c, 39j (mf).
Diplocephalus picinus Schaible & Gack, 1987: 174, f. 2, 4-5, 7 (m prosoma).
Diplocephalus picinus Eskov, 1988c: 25, f. 46 (m).
Diplocephalus picinus Tanasevitch, 1990: 111, f. 22.24, 24.44, 28.12 (mf).
Diplocephalus picinus Heimer & Nentwig, 1991: 142, f. 398 (mf).
Diplocephalus picinus Frick, Nentwig & Kropf, 2010: 309, Suppl. pl. 7A-O (mf).

Plaesiocraerus procer Simon, 1884a: 751, f. 639-640 (Dm).
Plaesiocraerus procer Simon, 1926: 379, 382, 497 (Df).
Plaesiocraerus procer Brignoli, 1971d: 202, f. 106-108, 110, 112-113 (mf).
Diplocephalus procerus Thaler, 1972a: 34, f. 24, 30-32 (m).
Diplocephalus procer Brignoli, 1979o: 37, f. 82-83 (mf).
Diplocephalus procer van Helsdingen, 1982b: 171, f. 20 (f).
Diplocephalus procer Lecigne, 2018b: 71, f. 8F-H (f).

Erigone protuberans O. Pickard-Cambridge, 1875b: 218, pl. 29, f. 24 (Dm).
Plaesiocraerus protuberans Simon, 1884a: 757, f. 649-651 (m, Df).
Diplocephalus protuberans Jackson, 1907a: 3, pl. 1, f. 10-15.
Diplocephalus protuberans O. Pickard-Cambridge, 1908a: 130, 144, pl. B, f. 49-50 (m).
Plaesiocraerus protuberans Simon, 1926: 381, 384, 497, f. 683 (mf).
Diplocephalus protuberans Denis, 1942a: 82, f. 1 (Df).
Diplocephalus protuberans Locket & Millidge, 1953: 295, f. 178D-F, 179G (mf).
Diplocephalus protuberans Casemir, 1961a: 197, f. 2.1-5 (m).
Diplocephalus protuberans Roberts, 1975: 144, f. 1 (f).
Diplocephalus protuberans Millidge, 1977: 34, f. 130 (m).
Diplocephalus protuberans Thaler, 1978a: 185, f. 11-14 (mf).
Diplocephalus protuberans Roberts, 1987: 86, f. 37d, 41a (mf).
Diplocephalus protuberans Heimer & Nentwig, 1991: 142, f. 401 (mf).
Diplocephalus protuberans Breitling, 2020: 345, f. 17F (f).
Diplocephalus protuberans Blick, 2024: 123, f. 5a-c (mf).

Diplocephalus protuberiscus Wunderlich, 2022: 52, f. 118-121 (Dm).

Diplocephalus pseudocrassilobus Gnelitsa, 2006a: 373, f. 1a-f, 2a-d (Dmf).

Diplocephalus (Hemistajus) rostratus Schenkel, 1934: 90, f. 1-2 (Dmf, new subgenus).
Hemistajus rostratus Schmölzer, in Janetschek, 1956: 479 (elevated from subgenus).
Diplocephalus rostratus Holm, 1970: 192, f. 7-9 (m).
Diplocephalus rostratus Thaler, 1970: 256, f. 1-9 (mf).
Diplocephalus rostratus Heimer & Nentwig, 1991: 142, f. 399 (mf).

Diplocephalus sphagnicolus Eskov, 1988c: 20, f. 32-37 (Dmf).

Erigone subrostrata O. Pickard-Cambridge, 1873f: 450, pl. 41, f. 14 (Dm).
Plaesiocraerus subrostratus Simon, 1884a: 777.
Lophocarenum cuneatum Emerton, 1909: 188, pl. 3, f. 6 (Dmf) [urn:lsid:nmbe.ch:spidersp:060653].
Evansia subrostrata Simon, 1926: 501.
Diplocephalus maculifrons Kulczyński, 1926: 44, pl. 2, f. 7 (Df) [urn:lsid:nmbe.ch:spidersp:060656].
Diplocephalus cuneatus Crosby & Bishop, 1928b: 1046.
Chocorua cuneata Crosby & Bishop, 1933b: 164, pl. 9, f. 216-222 (mf).
Diplocephalus subrostratus Eskov, 1988c: 23, f. 40-45 (mf, T from Evansia, S of Diplocephalus cuneatus and D. maculifrons).
Diplocephalus subrostratus Paquin & Dupérré, 2003: 98, f. 914-917 (mf).

Plaesiocraerus tiberinus Caporiacco, 1936c: 347, f. 3 (Dm).

Diplocephalus toscanaensis Wunderlich, 2011: 295, f. 126-130 (Dm).
Diplocephalus toscanensis Wunderlich, 2021: 7, f. 12-19 (m, Df, lapsus).

Diplocephalus transcaucasicus Tanasevitch, 1990: 50, f. 17.1-4, 18.1-2 (Dmf).

Diplocephalus turcicus Brignoli, 1972b: 167, f. 9-15, 17 (Dmf).
Diplocephalus turcicus Brignoli, 1974e: 496, f. 4 (f).
Diplocephalus turcicus Bosmans et al., 2009: 20, f. 7-12 (mf).

Diplocephalus uliginosus Eskov, 1988c: 25, f. 47-52 (Dmf).