Descrição original: Mansfield, W. C. (1925). Miocene gastropods and scaphopods from Trinidad, British West Indies. Proceedings of the United States National Museum. 66(2559): 1-65, pls. 1-10., available online at https://repository.si.edu/bitstream/handle/10088/15365/USNMP-66_2559_1925.pdf page(s): 28-29, pl. 4, fig. 5 [details]