Examination of 18 specimens from Costa Rica shows no differences in scutellation, nor geographic segregation of two populations.
There are only ten tail-feathers, and the scutellation of the tarsus is like that of Xenicus.
The scutellation resembles that of other species of Agkistrodon.
In other characters of scutellation the specimens are highly variable.
The scutellation of the cottonmouth closely resembles that of the other species of Agkistrodon.
In scutellation these specimens are like T. dorsalis cyclides.
The subspecies of P. deppei have been defined on characters of coloration and scutellation.
Of these, Cyclagras, Hypsirhynchus, and Pseudablabes have round pupils and certain differences in scutellation.