NEW NORTH-AMERICAN PLATYNUS BONELLI (COLEOPTERA, CARABIDAE), A KEY TOSPECIES NORTH OF MEXICO, AND NOTES ON SPECIES FROM THE SOUTHWESTERN UNITED-STATES

Platynus indecentis, new species, is described from northeastern North America, and Platynus cazieri, new species, and Platynus cohni, new s pecies, are described from Arizona. Platynus indecentis is a cryptic s ibling of the widespread P. decentis (Say), and is known to date only from sphagnum bog habitats. Platynus cazieri appears closely related t o P. aphaedrus Chaudoir of Veracruz, Oaxaca, and Chiapas, Mexico, wher eas P. cohni is considered a member of the subgenus Trapezodera Casey. Other Trapezodera species range from the Transvolcanic Sierra of Mexi co south to Chiapas. A key to the species of Platynus Bonelli north of Mexico, and distributional notes for species occurring in the southwe stern United States are provided. Platynus brunneomarginatus (Mannerhe im) exhibits color polymorphism characterized by an abrupt transition zone in the mountains surrounding the southern end of the Central Vall ey, California.