| Summary: | 262 p. : ill., maps 27 cm. Includes bibliographical references (p. 246-255) and index. "The genus Rhadinaea contains 45 species of small to medium-sized snakes that dwell on the American mainland between latitudes 35° North (Cape Hatteras, North Carolina) and 35° South (east-central Argentina), from sea level to 3200 meters of elevation. Most species seem to be diurnal foragers of the forest floor, although several are probably highly secretive and even semifossorial; they feed principally on amphibians and lizards. The primary habitats and routes of dispersal are pine-oak woodlands and cloud forests of Mexico and upper Central America and humid, tropical broadleaf forests, including montane and lowland rain forests. The generic limits are vague, in part because characters customarily utilized in distinguishing snake genera break down within single species of Rhadinaea. A variety of morphological information is useful in the taxonomy of Rhadinaea, but species can largely be identified on the basis of color pattern, and the hemipenis proves to be a particularly important source of clues to intergeneric and intrageneric relationships. Underwood's recent expansion of the Natricidae to include Rhadinaea and allied genera is not accepted as a natural arrangement, and the genus is retained in the family Colubridae. Eight species groups are recognized, primarily on the basis of characteristics of the hemipenis, color pattern, and maxillary dentition. The godmani group (11 species) has its ancestral homeland and center of dispersal in Nuclear Central America and is considered closest to the basic stock that gave rise to certain other species groups of Rhadinaea and to the genera Trimetopon and Coniophanes. One evolutionary trend seen within the godmani group is the reduction from 21 to 19 to 17 rows of dorsal scales. Rhadinaea godmani is shown to be an unexpectedly wide-ranging species with a disjunct distribution; the possibility of genetic interchange between this species and R. hemsteadae, on the Meseta Central ...
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