original descriptionDell R. K. 1964. Antarctic and subantarctic Mollusca: Amphineura, Scaphopoda and Bivalvia. Discovery Reports 33: 93-250, pls. 2-7., available online athttp://viewer.soton.ac.uk/nol/image/140763633/206/#head page(s): 142-143, pl. 2, figs 1,2 [details]