F. B. Meek and F.V. Hayden. 1858. Descriptions of new organic remains collected in Nebraska territory in the year 1857, by Dr. F. V. Hayden, geologist to the exploring expedition under the command of Lieut. G. K. Warren, Top. Engr. U. S. Army, together with some remarks on the geology of the Black Hills and portions of the surrounding country. Proceedings of the Academy of Natural Sciences of Philadelphia 10:41-59 [G. Webster/G. Webster]