INTRODUCTION 301
Acknowledgments 301
Materials and Methods 302
ANALYSIS OF DATA 303
External Morphology 303
Color and Pattern 307
Osteology 307
Tadpoles 310
Breeding Call 312
SYSTEMATIC ACCOUNTS 314
_Ptychohyla_ Taylor, 1944 314
Key to Adults 315
Key to Tadpoles 315
_Ptychohyla euthysanota_ Group 315
_Ptychohyla euthysanota_ 315
_Ptychohyla euthysanota euthysanota_ (Kellogg) 315
_Ptychohyla euthysanota macrotympanum_ (Tanner) 320
_Ptychohyla leonhardschultzei_ (Ahl) 323
_Ptychohyla spinipollex_ (Schmidt) 327
_Ptychohyla schmidtorum_ Group 331
_Ptychohyla schmidtorum_ 331
_Ptychohyla schmidtorum schmidtorum_ Stuart 331
_Ptychohyla schmidtorum chamulae_ Duellman 334
_Ptychohyla ignicolor_ Duellman 337
DISTRIBUTION AND ECOLOGY 340
Geographic Distribution of the Species 340
Habitat Preference 342
Interspecific Competition 343
Reproduction and Development 344
PHYLOGENY OF PTYCHOHYLA 345
_Ptychohyla_ as a Natural Assemblage 345
Generic Relationships 346
Interspecific Relationships 347