Didymograptus bifidus (Hall, 1865)

1858     Graptolithus bifidus n. sp. — Hall, pp. 130

1865     Didymograptus bifidus — Hall, pp. 73, fig. 1:16-18; 3:9-10

1901     Didymograptus bifidus — Elles and Wood, pp. 42, fig. 4:1a-f

1934     Didymograptus bifidus — Hsü, pp. 39, fig. 2:10a-c

1937     Didymograptus bifidus — Ekström, pp. 26, fig. 2:9-15

1947     Didymograptus bifidus — Ruedemann, pp. 327, fig. 54:11-16

1960     Didymograptus bifidus (Hall) — Obut, pp. 152, fig. 5:2-2a

1962     Didymograptus bifidus (J. Hall) — Berry, pp. 294, fig. 1a-e, 2a-b

1970     Didymograptus bifidus (J. Hall, 1865) — Skevington, pp. 426, fig. 9a

1988     Didymograptus (Didymograptellus) bifidus (J. Hall) — Williams et Stevens, pp. 41, fig. 12; 13:8-13

2006     Didymograptus (Didymograptellus) bifidus (J. Hall) — Jackson et Lenz, fig. 8 o-q; u-w