"A New Pocket Gopher (Thomomys) and A New Spiny Pocket Mouse (Liomys) from Michoacán, Mexico" by E. Raymond Hall and Bernardo Villa R. is a scientific publication written in the mid-20th century. This work focuses on the taxonomic identification and description of two previously unrecognized subspecies of rodents from the region of Pátzcuaro in Michoacán, Mexico. It presents findings from field studies and provides detailed morphological analyses of the species in question. The publication introduces the subspecies "Thomomys umbrinus pullus" and "Liomys irroratus acutus," detailing their characteristics, habitat, and distinctions from related species. The authors document the ecological context in which these animals were found, noting their coexistence in specific geological areas. Through quantitative measurements and physical descriptions, the work contributes to the understanding of species diversity in rodent populations within this geographic area, showcasing the subtle differences that account for the classification of these new subspecies. The paper is both an essential reference for mammalogists and a contribution to the broader field of wildlife biology in Mexico. (This is an automatically generated summary.)