The marked ontogenetic variation in _S. sordida_ is considered in more detail in the account of that species, but it is pertinent to the present discussion to note that with respect to some features of the skull some young breeding specimens of _S. sordida_ are intermediate in appearance between large females of _S. sordida_ and adults of _S. puma_. In some breeding males (usually the smaller individuals) of _S. sordida_ the bony part of the ethmoid terminates at the anterior edge of the orbit and is widely separated from the nasals by cartilage. In small individuals _S. sordida_, especially in males, and in adults of _S. puma_ the tegmen tympani are relatively short, whereas in adult females of _S. sordida_ these elements are long and slender. In the smaller specimens of _S. sordida_ and in _S. puma_ the squamosal is small; it extends only about one-fourth of the distance to the maxillary in the smaller _S. sordida_ and about one-half the distance in _S. puma_. The more massive squamosal in large adult females of _S. sordida_ extends at least two-thirds of the distance to the maxillary. Table 4.--Comparative Cranial Osteology of Smilisca. ===============+==============================+======================= Character | _S. baudini_ | _S. cyanosticta_ ---------------+------------------------------+----------------------- | | Alary Processes| Four times as high as | Three times as high | lateral wing of premaxillary;| as lateral wing of | anteriorly | premaxillary; | convex. | anteriorly | | convex. | | Nasals | Long, wide anteriorly, | Long, widest | narrowing posteriorly; | posteriorly; | attached to ethmoid. | attached to | | ethmoid. | | | | | | Ethmoid | Long; entirely ossified; | Long, entirely | smooth margins. | ossified; | | smooth margins. | | Frontoparietal | Small, ovid fontanelle | Large fontanelle, two | present or absent; | and one-half times as | long, pointed postorbital | long as wide; narrow | processes curving | supraorbital flanges | along posterior | with irregular margins. | border of orbit. | | | Squamosal | Large: anterior arm | Large; anterior arm