"A New Pocket Gopher (Genus Thomomys), from Eastern Colorado" by E. Raymond Hall is a scientific publication written in the early 1950s. This work represents a study focused on the taxonomy of pocket gophers, specifically examining previously misclassified specimens from east-central Colorado and proposing a new subspecies. The text is aimed at scholars and researchers in the field of mammalogy and provides detailed anatomical and geographic information regarding this rodent species. In this publication, Hall identifies and describes a new subspecies of the pocket gopher, named "Thomomys talpoides retrorsus", which was discovered in the region of eastern Colorado. By analyzing specimens and their characteristics, Hall distinguishes this subspecies from others previously categorized and offers a thorough comparison based on various skull measurements, coloration, and other anatomical features. The study not only clarifies the subspecific identity of these gophers but also addresses previous taxonomic confusion, contributing valuable knowledge to the understanding of mammalian diversity in North America. (This is an automatically generated summary.)