_Tuxpan._--Fifteen specimens (UMMZ 115227), 28.7-33.0 (30.5) mm. Dorsolateral dark stripe or row of dashes in all specimens; dark spots in lateral green fields, at least posteriorly in most; dark spots posteriorly in the dorsal green field in five; lateral dark stripe separated from dorsolateral stripe in all specimens; lateral white line extends to the groin in all specimens. As can be seen from the above descriptions, the distinguishing characters of _Hyla microeximia_--confluence of lateral and dorsolateral dark stripes posteriorly, extent of lateral white stripe, and distribution of dark spots dorsally--are found in individuals from all of the populations sampled. In the samples from western Michoacán there is a higher incidence of _microeximia_-like frogs than in those from other parts of the state. _Hyla eximia_ is a wide-ranging species varying greatly geographically and individually. A thorough review of the species and related members of the _Hyla eximia_-group is necessary before certain populations can justifiably be segregated as subspecies or species. In Michoacán _Hyla eximia_ has been collected in mesquite-grassland, pine-oak forest, and cultivated areas on the Mexican Plateau from 1500 to 2300 meters; apparently it is absent from the Sierra de Coalcomán. This is the most abundant frog on the southern part of the Mexican Plateau; in the rainy season breeding choruses are found in temporary pools and in the marshes adjacent to the permanent lakes. ~Hyla lafrentzi~ Mertens and Wolterstorff _Hyla lafrentzi_ Mertens and Wolterstorff, Zool. Anz., 84:235, August 25, 1929.--Desierto de los Leones, Distrito Federal, México. Cerro San Andrés (26); Opopeo (9). In March, 1949, James A. Peters collected this species at elevations of 2400 to 2800 meters on the west slope of Cerro San Andrés. The frogs were found beneath logs and rocks in a damp canyon in coniferous forest. Among the juveniles in this series is a completely transformed individual (UMMZ 102093) having a snout-vent length of 14.5 mm. Five adults have snout-vent lengths of 36.2-39.5 (38.0) mm. _Hyla lafrentzi_ has noticeably longer hind limbs than _H. eximia_; in the former, when the hind limb is brought forward along the body, the tibiotarsal articulation extends to the snout. There are dark transverse bands on the hind limbs; the dorsolateral stripe is broken into an anterior and a posterior segment, and the latter is narrowly bordered by white in most specimens. _Hyla lafrentzi_ occurs at higher elevations than any other frog in Michoacán; the locality records from throughout the range indicate that it is restricted to pine and pine-fir forests. In these habitats it replaces _Hyla eximia_, which inhabits the lower pine-oak forests and mesquite-grassland on the Mexican Plateau. Ponds are absent at places where _Hyla lafrentzi_ has been collected; possibly the eggs are laid in streams. ~Hyla smaragdina~ Taylor