CEPHALOPODA

Groves, Lindsey T. & Squires, Richard L., 2018, Annotated Catalog of the Fossil Invertebrates Described by, and Named for, William More Gabb (1839 - 1878), Zootaxa 4534 (1), pp. 1-150 : 111

CEPHALOPODA

GENERA AND HIGHER TAXA

Diptychoceras Gabb, 1869b: 143 . Type species: Diptychoceras laevis Gabb, 1869b: 144–145 , pl. 25, figs. 21–21b, by OD.

Helicancylus Gabb, 1869b: 140–141 . Type species: Ptychoceras aequicostatus Gabb, 1864b: 74 , pl. 25, fig. 20, by monotypy. Remarks: Helicancylcus is a nomen dubium, according to Vermeulen et al. (2013: 30).

Polorthidae Gabb, 1872a: 260 –261. Remarks: Gabb (1872a) erected this family based on examination of the bivalve Polorthus americana (Gabb) , believing it to be a cephalopod and designated Polorthus as the type genus of the new family. Stephenson (1937: 60) demonstrated that P. americana is a boring bivalve.

Ptiloteuthis Gabb, 1869b: 128 . Type species: Ptiloteuthis foliatus Gabb, 1869b: 128–129 , pl. 19, fig. 4, by OD. Remarks: Actually a Cretaceous insect wing, according to Rehn (1939: 1–2).