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.