_leprus_ group: digital pads not or only slightly expanded, rounded in outline; first finger longer or shorter than second; snout acuminate or subacuminate, not rounded; outer metatarsal tubercle conical; digits lacking distinct lateral fringes. content: _cystignathoides_, _leprus_ and _rubrimaculatus_. _longipes_ group: digital pads widely expanded, triangular in outline; first finger shorter than second; snout acuminate; outer metatarsal tubercle not conical; digits bearing lateral fringes. content: _dennisi_ and _longipes_. _marnockii_ group: digital pads expanded, rounded to truncate in outline; first finger equal in length to second or slightly shorter; snout rounded; outer metatarsal tubercle not conical; digits lacking lateral fringes; generally stout-bodied frogs. content: _guttilatus_, _marnockii_, and _verrucipes_. _modestus_ group: digital pads expanded, truncate in outline; first and second fingers subequal in length, first usually slightly shorter than second; snout subacuminate; inner metatarsal tubercle twice as large (or larger) as outer metatarsal tubercle; digits bearing poorly-defined lateral fringes. content: _interorbitalis_, _modestus_, _nivocolimae_, _pallidus_, and _teretistes_. _pipilans_ group: digital pads not or only slightly expanded, truncate in outline; first finger equal in length to second; snout subacuminate; metatarsal tubercles subequal in size; digits lacking lateral fringes. content: _pipilans_. _Acknowledgments._--For loan of specimens, I am indebted to Richard J. Baldauf, Texas A & M University (TCWC); W. Frank Blair, University of Texas (TNHC); Charles M. Bogert and Richard G. Zweifel, American Museum of Natural History (AMNH); James E. Boehlke and Edmond V. Malnate, Academy of Natural Sciences of Philadelphia (ANSP); Robert F. Inger and Hymen Marx, Field Museum of Natural History (FMNH); Ernest A. Liner (EAL); Michael Ovchynnyk, Michigan State University collection (MSU); James A. Peters, United States National Museum (USNM); Douglas A. Rossman, Louisiana State University Museum of Zoology (LSUMZ); Hobart M. Smith, University of Illinois Museum of Natural History (UIMNH); Charles F. Walker, University of Michigan Museum of Zoology (UMMZ); and John W. Wright, Los Angeles County Museum (LACM). Specimens in the collection at the University of Kansas Museum of Natural History are identified as KU. The abbreviations EHT-HMS refer to the Edward H. Taylor-Hobart M. Smith collection and FAS to the Frederick A. Shannon collection. The type-specimens from these collections are now in the Field Museum of Natural History and the University of Illinois Museum of Natural History.