Epithemia emarginata Andrews

Length: 97

Width: 18

Striae: 8

Costae: 4

Collection 1157a

More information

This is a scanned in image from a previous
picture of the specimen. The slide was missing
so no new pictures could be taken.

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Authority information

Epithemia emarginata Anderws, Jour. Paleont., 42(1):244. 1968 (Patrick and Reimer 1975).

More information

Valve has a variously bent concave ventral margin and a convex dorsal margin. Apices sometimes somewhat protracted and much narrower than the middle part of the valve. The central nodule of the raphe is at or below the middle of the valve's width. Alveoli are narrower at central nodule. Closely related to E. turgida and may be abnormal forms of it in some cases. May be proven that it is an abnormal form of E. turgida but it has been recognised as a distinct species. closest to E. turgidevar. plicata. Seems to prefer cool water. (Patrick and Reimer 1975).

Type Locality

USA, Lake Michigan. (Patrick and Reimer 1975).


    Epithemia irregularis Andrews, U.S. Geol. Surv. Prof. Pap., 523-A:A-22, pl. 3 figs 22-25. 1966 ( non epithemia irregularis Fritsch & Rich, Trans. Roy. Soc. South Africa, 12(4):277-284. 1925)
    Epithemia andrewsii Stoerm. And Yang, Special Report #47, University of Michigan, p 67. 1967 (nomen superf) (Patrick and Reimer 1975).

Size ranges and morphology

  • Length is 43 to 100 micrometers (Patrick and Reimer 1975).
  • Width is 16 to 20 micrometers (Patrick and Reimer 1975).
  • Costae are about 3-5 in 10 micrometers (Patrick and Reimer 1975).
  • Alveoli rows are 7 to 10 in 10 micrometers (Patrick and Reimer 1975).