Comments on the Taxonomy and Geographic Distribution of Some North American Rabbits

It is a zoological book. Examination of cottontail rabbits from Arizona in the Biological Surveys Collection and the United States National Museum indicates that Sylvilagus audubonii can be distinguished from Sylvilagus nuttallii and Sylvilagus floridanus by the larger (more inflated) tympanic bullae. Topotypes of Sylvilagus nuttallii pinetis and other specimens from Alpine, Mt. Thomas, Springerville, the Prieto Plateau at 9000 feet on the south end of the Blue Range, and the Tunitcha Mountains are characterized by a posteriorly pointed supraoccipital shield and a long, wide space between the braincase and the posterior extension of the supraorbital process. The cottontails with equally small tympanic bullae from more western and more southern localities are referable to Sylvilagus floridanus holzneri on the basis of a posteriorly truncate or emarginate supraoccipital shield and a narrower and shorter space (usually a 'foramen') between the braincase and the posterior extension of the supraorbital process.