The Birds of Wyoming. E-book. Formato PDF Wilbur C. Knight   -  Forgotten Books, 2017  - 

The published notes have not been satisfactorily disposed of. Some of the earlier work is a half century old, and to make this conform to the present nomenclature Without having the specimens to consult, is more difficult than it appears on the onset. Where the early data could be placed unquestionably this Was done. In other cases they were as a rule placed in accordance with the recent geographical distribution of the species. Since there are many eastern and western forms that mingle in eastern Wyoming it will be necessary to have extensive collections made before many points can be settled. The fact that many new species and varieties have been. Named during the last quarter of a century caused a great deal of confusion, since in many cases it was impossible to tell anything about the specimens that had been collected.