Hall, J. & R.P. Whitfield. 1869. Preliminary Notice of the Lamellibanchiate Shells of the Upper Helderberg, Hamilton and Chemung Groups, with others from the Waverly Sandstones (2): 1-80.
(intro'd as sub-gen. of Modiolopsis Hall, 1847)
Hall & Whitfield, 1869. Prelim. Not. Lamell. Shells (2): 27.
Type species: Nyassa arguta Hall & Whitfield, 1869 (orig. desig.) = Nyassa arguta
(intro'd as sub-gen. of Modiolopsis Hall, 1847)
Hall & Whitfield, 1869. Prelim. Not. Lamell. Shells (2): 28.
Type species: Nyassa arguta Hall & Whitfield, 1869 (orig. desig.) = Nyassa arguta
Hall & Whitfield, 1869. Prelim. Not. Lamell. Shells (2): 28.