W. E.  Ritter, ?The structure and affinities of Herdmania claviformis, the type of a new genus and family of ascidians?, Mark Anniversary Volume, vol. 12, pp. 235-261, 1903.

R.  Hartmeyer, ?Die Ascidien der Arktis?, In Romer and Schaudinn, Fauna Arctica, vol. 3, pp. 93-412, 1903.