Only P. spinipollex has lateral processes anteriorly on the xiphisternum; in the other species the xiphisternum is deeply bell-shaped.
"A Review of the Middle American Tree Frogs of the Genus Ptychohyla"
William E. Duellman
The lower part of the body was very much bruised, both posteriorly and anteriorly.
"Report on Surgery to the Santa Clara County Medical Society"
Joseph Bradford Cox
anteriorly it is flattened from before to behind and directed inward and upward.
"Common Diseases of Farm Animals"
R. A. Craig, D. V. M.