The systematic status of the populations of lizards assignable to _Cnemidophorus sacki_ in western México (Sonora southward to Jalisco) has been reviewed in detail by Zweifel (1959, Bull. Amer. Mus. Nat. Hist, 117 (2):57-116), who stated that the use of the specific name _sacki_ for the western populations rests upon a reasonable, but as yet unproved, assumption that intergradation occurs. Although Zweifel examined specimens of the nominal subspecies from the upper Balsas Basin, he did not study specimens from the intervening area--the Tepalcatepec Valley in Michoacán. Field studies and the examination of large series of preserved specimens of _Cnemidophorus_ from the Tepalcatepec Valley sh…
Your support pays for translating these classics into more languages.
Support for $12/month DonateSubscribers read with instant translation, without waiting for the free daily limit.