[Illustration: PLATE 2 FIG. 1. Nest and eggs of _Pseudoeurycea belli_ beneath a rock at San Juan de Parangaricutiro. Approx. natural size. FIG. 2. Multiple egg clutches of _Phyllomedusa dacnicolor_ from Coalcomán, Michoacán. 1/3 ×. [Illustration: PLATE 3 FIG. 1. Adult male of _Tomodactylus angustidigitorum_ from Paracho, Michoacán. × 4. FIG. 2. Adult male of _Tomodactylus fuscus_ from Los Cantiles, Michoacán. ×4. [Illustration: PLATE 4 FIG. 1. Adult male of _Tomodactylus nitidus_ nitidus from Tuxpan, Michoacán. ×. FIG. 2. Adult male of _Tomodactylus nitidus orarius_ from Tecolapa, Colima. × 4.] [Illustration: PLATE 5 FIG. 1. Adult male of _Tomodactylus nitidus_ petersi from Apatzingán, Michoacán. × 4. Fig. 2. Adult male of _Tomodactylus rufescens_ from Dos Aguas, Michoacán. × 4.] [Illustration: PLATE 6 FIG. 1. Adult male of _Hypopachus caprimimus_ from Tuxpan, Michoacán. × 2-1/2. FIG. 2. Adult male of _Hypopachus oxyrrhinus ovis_ from Tangamandapio, Michoacán. × 3.] 4. A distinct, pale-colored, diagonal lateral stripe is found in females only from localities outside of the Balsas-Tepalcatepec Basin; females from the basin have a spotted dorsum. 5. Males from the Balsas-Tepalcatepec Basin usually have a broad middorsal line that is yellow or pale tan; those from outside the basin have either a narrow middorsal line or none. 6. Males from the Balsas-Tepalcatepec Basin have low, scattered dorsal tubercles (Fig. 3); males from outside the basin have a concentration of tubercles in a broad band on the back (Fig. 4). Therefore the nature of the cranial crests is of little value in separating two populations, but the color pattern of the females and the nature of the dorsal tubercles of the males do show distinct differences. Furthermore, certain differences in size and proportion are evident; _Bufo marmoreus_ is a slightly larger toad and has a relatively longer tibia and longer head than _perplexus_ (Table 2). TABLE 2.--COMPARISON OF CERTAIN MEASUREMENTS AND PROPORTIONS IN BUFO MARMOREUS AND B. PERPLEXUS. (MEANS ARE GIVEN IN PARENTHESES BELOW THE RANGES.)