↑Ulrich, E. O.; Scofield, W. H. (1894) The Lower Silurian Lamellibranchiata of Minnesota. In E. O. Ulrich, W. H. Scofield, J. M. Clarke, & N. H. Winchell, eds., Final Report of the Geological and Natural History Survey of Minnesota, vol. 3, part 2, The Geology of Minnesota. Paleontology. p. 475–628, pl. 35–46. Published and distributed under separate cover prior to publication of entire vol. 3 in 1897. Systematics of Bivalvia by Ulrich alone.
