William Edward Duellman

“ In Michoacán the rainfall is heaviest on the southern slopes of the Sierra de Coalcomán and somewhat less so on the southwestern slopes of the Cordillera Volcánica. At these relatively low elevations (150 to 600 meters) there is tropical semi-deciduous forest, characterized by relatively dense shade throughout the year and by a leaf mulch on the ground. This type of forest forms the gallery forest along the larger streams in the Balsas-Tepalcatepec Basin and on the Pacific Coastal Plain. ”

“ Lying between the Tepalcatepec Valley and the Pacific Ocean, and east of the Río Coahuayana and west of the Río Balsas, is an isolated highland mass, the Sierra de Coalcomán. This mountain range rises to elevations of slightly more than 3000 meters. It has a length of about 200 kilometers and a width of about 80 kilometers. Except for a relatively low connection with the Cordillera Volcánica, the Sierra de Coalcomán is isolated from other mountain ranges in southwestern México. ”

“ In the Tepalcatepec Valley T. dorsalis postremus is most frequently found at night in the rainy season, at which time the snakes are abundant near temporary pools where frogs are breeding. The absence of specimens from the coastal lowlands of Guerrero, Michoacán, and Colima indicate that, although the species inhabits the lowlands of the Tepalcatepec Valley, its range does not include the coastal lowlands. ”

“ Many small mountain ranges rise from the plateau and break the continuity of the rolling table-land. Located on the southern part of the Mexican Plateau in Michoacán are several lakes, the largest of which are Lago de Chapala, Lago de Cuitzeo, and Lago de Pátzcuaro.
Bordering the southern edge of the Mexican Plateau is a nearly unbroken chain of volcanos, the Cordillera Volcánica. The highest peaks in Michoacán, Cerro San Andrés (3930 meters) and Cerro de Tancítaro (3870 meters) , are in this range. Parts of the Cordillera Volcánica in Michoacán are known by separate names ”

“ Smith and Taylor (1945:148) gave the range of Trimorphodon tau as: "Central Guerrero, in the Sierra Madre del Sur; central Oaxaca; and the edge of the plateau in central Michoacán." They gave the range of Trimorphodon upsilon as: "Southern Chihuahua south to central Michoacán, east to central Hidalgo." Specimens referable to T. tau have been found at La Joya de Salas, near Ciudad Victoria, and near Llera, Tamaulipas (see Smith and Darling, 1952:85, and Martin, 1958:74) . Some of these specimens also show combinations of characteristics of T. tau and T. upsilon. Smith and Darling (loc. cit.) ”

“ The application of the above criteria to specimens from Michoacán has not resulted in the recognition of two species. The majority of the specimens have the supraorbital semicircles separated by at least one small scale; the head scales, with the exception of those on the snout in a few individuals, are smooth; the dorsal scales are only slightly smaller than the ventrals. In other characters of scutellation the specimens are highly variable. ”

“ The systematics and distribution of Pseudemys scripta in México and Central America are poorly understood. Smith and Taylor (1950b:32) recorded this turtle from the Pacific lowlands of Sinaloa, Jalisco, Oaxaca, and Chiapas. This species is represented by vicarious populations throughout the Atlantic lowlands of México, northwestern México, over much of the United States, and also in Baja California. Along the Pacific coast of México the species seems to be extremely rare, or, at least, only locally abundant. ”

“ Although the type series of Hyla smaragdina consists of immature specimens, the males in that series do possess vocal sacs. Since these were not breeding individuals, the sacs are not well developed. The characters of the anal tubercles and the relative width of the head are of no value in separating the two species. The apparently aestivating individuals comprising the type series of Hyla smaragdina, and the type of Hylella azteca, which also was found in a bromeliad, were green in life. Of the calling males found on the coast of Michoacán, most were yellowish tan when found ”

“ The new species was diagnosed as differing from P. inflata in having less webbing on the feet, a poorly developed supratympanic fold, a more pustulate dorsum, and marked differences in dorsal pattern, color, and nature of antebrachial banding. The significance of the webbing was questioned by Shannon and Humphrey. The nature of the supratympanic fold and dorsal pustules changes with age (Duellman, 1956a:31) . Phrynohyas inflata is known to attain a snout-vent length of 95 mm. Dermal structures that undergo ontogenetic change are of little importance in comparing a juvenile with a large adult. ”

“ The males in life have an orange throat fan. Anoles of this kind have been found in Michoacán, Colima, Jalisco, Nayarit, and southern Sinaloa. Near Oaxaca, Oaxaca, specimens were collected that superficially resemble those from Michoacán and farther north. These have low keels on the snout scales, dorsals somewhat larger than the ventrals, and a pink throat fan. In ten males from Oaxaca the size of the dorsal scales relative to that of the ventrals is 1.00:0.83; the same ratio for 25 males from Michoacán is 1.00:1.08. ”

“ The skin in specimens from Ostula and Colima is slightly granular. The dorsal ground color of D. reticulata is yellowish brown with dark reticulations; the dorsal ground color of D. spatulata is olive-green. Specimens from Ostula and Colima most closely resemble those from Tehuantepec in coloration, but the reticulations are more coarse, and the ground color has an olive-green [Pg 43] tint. Diaglena reticulata also differs from D. spatulata in having a larger over-all size, slightly broader head, a narrower interorbital distance, and a more pointed snout with a deeper labial shelf (Table 4) . ”

“ 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. ”

“ The type and only known specimen of Geophis maculiferus (UIMNH 25078) is a female having 140 ventrals and 30 caudals, dorsal scales in 15 rows, one postocular, and an anterior temporal. Only one other species in México has dorsal scales in 15 rows and has an anterior temporal; that species is G. incomptus, which differs from G. maculiferus in having six or seven lower labials, instead of five, and in having the edges of the ventrals dark, instead of a uniformly cream-colored belly. ”

“ In México Bufo coccifer has been collected only in semi-xeric habitats, but to the south, from Guatemala to Costa Rica, it has been found in more upland and humid habitats. Southern specimens are darker than those from the north, a possible correlation with the differences in habitat. ”

“ Furthermore, he supplied me with the following observations based on his field work along the coast of Michoacán from the Río Coahuayana to Maruata from March 1, to April 15, 1956. At that time many sea snakes were observed; in some places living and dead individuals were seen on the beaches; innumerable snakes were seen in the surf. When live individuals were taken from the beach and thrown into the ocean, they usually swam to shore. Many partially eaten individuals were seen protruding from crab holes. ”

“ Both species of Diaglena inhabit tropical scrub forest; none has been found in the more humid and tropical semi-deciduous forests. Humid forest replaces the scrub forest in the lowlands of southern Nayarit and [Pg 44] northern Jalisco; possibly this forest acts as a barrier to the distribution of Diaglena and thus serves as a divider between the ranges of D. spatulata to the north and D. reticulata to the south.
Pternohyla fodiens Boulenger ”

“ The range of this species includes the Sierra Ajusco in México and Morelos and thence westward to the Serranía Ucareo in Michoacán. The specimen from 28 kilometers east of Morelia was found in an oak forest on a steep hillside at an elevation of 2100 meters. One from Los Cantiles was calling from a steep cliff at [Pg 40] an elevation of 2200 meters in pine-oak forest. This specimen (UMMZ 119156) in life had a pale olive-brown dorsum with irregular dark brown mottling and transverse bars on the limbs. The interorbital bar, the upper arms, and the tips of the dorsal pustules were pale orange ”

“ The small montane rattlesnakes belonging to the species C. pricei, C. pusillus, and C. triseriatus present a problem in systematics and distribution worthy of intensive investigation. A knowledge of the [Pg 124] distribution and relationships of the various populations of these snakes, together with other species also living in isolated populations on the higher mountains in México, probably will be of great significance in understanding dispersal and differentiation of animals during the Pleistocene. ”

“ This large tree frog has been found only in the lowlands below elevation of about 1000 meters, usually in arid tropical scrub forest. Calling males were heard on rainy nights throughout the rainy season; in nearly every instance both males and females were found in low trees and bushes. On summer nights when there had been no rain, adults were found sitting on bushes in the scrub forest. ”

“ In the meantime, Bogert and Oliver (1945:359) presented a reinterpretation of Smith's data and suggested that T. vicinus, which differs from T. dorsalis cyclides only in lacking a middorsal stripe, "... is not a species, but only a pattern phase, possibly a simple mutant of T. e. eques" (= T. dorsalis cyclides, by present arrangement) . Milstead (1953) agreed with Bogert and Oliver on the status of T. vicinus; furthermore, on the basis of only a few specimens, Milstead concluded [Pg 115] that T. cyrtopsis postremus was not subspecifically distinct from T. cyrtopsis cyclides. ”

“ Although this species has a rather extensive range in the Balsas-Tepalcatepec Basin in the state of Michoacán, Guerrero, Morelos, and Puebla, it is only locally abundant in that area. Usually these lizards are found on rocky cliffs in which there are many crevices for cover. Sceloporus gadowae is abundant on a conglomerate cliff along the Río Marquez south of Lombardia. ”

“ I have seen several preserved specimens from the vicinity of Tehuantepec, Oaxaca. Although they probably belong to this group, those specimens differ from both A. nebulosus and A. nebuloides in their larger size, relatively larger head, and much larger throat fan.
Aside from the minor variation in scutellation, specimens of Anolis nebulosus from Michoacán vary greatly in coloration. Usually the females have some form of a broad middorsal pale-colored band. In life this is dull yellow, tan, or orange. Two females from Dos Aguas are strikingly different ”

“ Systematic studies based at least in part on specimens from Michoacán have resulted in a redefinition of nine species and subspecies: Bufo marmoreus, Bufo perplexus, Anolis nebulosus, Anolis nebuloides, Sceloporus bulleri, Sceloporus heterolepis, Sceloporus melanorhinus calligaster, Hypsiglena torquata torquata, and Hypsiglena torquata ochrorhyncha.
Nine species that previously have been recognized as valid have been placed in synonymy. These are: Bufo horribilis Wiegmann, 1833, and Bufo angustipes Smith and Taylor, 1945, as synonyms of [Pg 142] Bufo marinus (Linnaeus) , 1758. ”