The preceding data on morphology, life histories, and behavior form the basis for the following interpretation of the phylogeny of _Ptychohyla_. Additional data are needed to support some of the ideas discussed below; many of the data that are available for _Ptychohyla_ are lacking for other, possibly related, hylids. The family Hylidae is composed of several hundred species, and most of the species are poorly known. Consequently, any attempt to place _Ptychohyla_ in the over-all scheme of hylid phylogeny would be premature at this time. But, as between the five species of two species-groups here recognized as constituting the genus _Ptychohyla_, some estimate of relationships can be made. First, it is necessary to determine the validity of the genus itself. Ptychohyla as a Natural Assemblage As stated in the diagnosis of the genus, the only character that sets this group of species apart from other hylids is the presence of ventrolateral glands in the breeding males. To many systematists the thought of being able to identify to genus only breeding males is sufficiently disturbing to cause them to view with disfavor the recognition of the genus. Nonetheless, the question is raised: Do the five species herein placed in the genus _Ptychohyla_ constitute a natural assemblage? If the genus is considered to be more than a category of convenience, that is to say, a group of related species having a common origin, the primary problem is to determine whether or not the five species form a phylogenetic unit.