are as follows: Eurypterus De Kay, 1825 ?Eurypterus cephalaspis Salter, 1856 – Silurian, England Uncertain placement. Only 3 of the specimens described in 1856 are probably Eurypterus, the rest probably belonged to Hughmilleriidae. Its name means 'shield head', from Greek ( 'head'), and ( 'shield or bowl'). Specimens recovered from Herefordshire, England. Eurypterus dekayi Hall, 1859 – Silurian, United States & Canada No raised scales on the posterior margin of the carapace or of the three front-most tergites. The rest of the tergites each have four raised scales. Four to six spines on each podomere of Appendages III and IV. Pretelson has large, rounded epimera without ornamentation on the margins. The species is very similar to E. laculatus. The species is named after James Ellsworth De Kay. Specimens recovered from New York and Ontario. Eurypterus flintstonensis Swartz, 1923 – Silurian, USA Probably a synonym of E. remipes or E. lacustris. Probably named after Flintstone, Georgia (?). Specimen recovered from eastern United States. Eurypterus hankeni Tetlie, 2006 – Silurian, Norway Small Eurypterus species, averaging at long. The largest specimen found is about in length. They can be distinguished by pustules and six scales at the rear margin of their carapaces. Appendages I to IV has two spines on each podomere. The postabdomen have small epimera. The pretelson has long pointed epimera. Telson has striations near its attachment to the pretelson. The species is named after Norwegian paleontologist Nils-Martin Hanken, of the University of Tromsø. Found in the Steinsfjorden Formation of Ringerike, Norway. Eurypterus henningsmoeni Tetlie, 2002 – Silurian, Norway Eurypterus with broad paddles and metastoma. Postabdomen has small epimera. Pretelson has large rounded epimera with imbricate scales (overlapping, similar to fish scales). It is very similar and closely related to E. tetragonophthalmus. The species was named after the Norwegian paleontologist Gunnar Henningsmoen. Found in Bærum, Norway. Eurypterus laculatus Kjellesvig-Waering, 1958 – Silurian, USA & Canada The visual area of the compound eyes of this species are surrounded by depressions. The ocelli and the ocellar mound are small. No pustules or raised scales on the carapace or the first tergite. It is probably closely related to E. dekayi. Its specific epithet means 'four-cornered', from Latin ('four-cornered, checkered'). Found in New York and Ontario. Eurypterus lacustris Harlan, 1834 – Silurian, USA & Canada = Eurypterus pachycheirus Hall, 1859 – Silurian, USA & Canada = Eurypterus robustus Hall, 1859 – Silurian, USA & Canada