NOTAS SISTEMATICAS SOBRE AVES MEXICANAS II

Resumen

Taxonomic and nomenclatural studies of several Mexican birds have led to conclusions somewhat at variance with part or all of the modern literature, or (in the case of Toxostoma rufum) modify the characters used to separate the races. Several races or current names, and two genera, are considered of doubtful validity, but Sittasomus griseicapillus harrisoni Sutton, Dumetella carolinensis ruficrissa Aldrich, and Volatinia jacarina diluta van Rossem are upheld. The lumping of sorne species of jays ("Cissilopha") and Polioptila by certain authors is not believed to be justified. Certain historical aspects of lcterus cucullatus and Pipilo aberti are discussed, and the
application of P. a. aberti and of the genus Hortulanus Vieillot is restricted. The nomenclatural instability which will result if the illconsidered new Rule 23 (b) of the lnternational Code of Zoological Nomenclature is allowed to remain is illustrated (Catoptrophorus).