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"Schizognathous skull of common fowl, nat. size, from nature, by Dr. R.W. Shufeldt, U.S.A. Letters as before; Pa, palatine. Schizognathism is a kind of " cleft palate" shown by the columbine and gallinaceous birds, by the wader at large, and many of the swimmers. In this general case, the vomer, whether large or small, tapers to a point in front, while behind it embraces the basisphenoidal rostrum, between the palatines; these bones and the pterygoids are directly articulated with one another and with the basisphenoidal rostrum, not being borne upon the divergent posterior ends of the vomer; the maxillo-palatines, usually elongated and lamelar, pass inwards over (under, when the skull is viewed upside-down, as it usually is) the anterior part of the palatines, with which they unite and then bend backwards, along the inner edge of the palatines, leaving a broader or narrower fissure between themselves and the vomer, on each side, and do not unite with one another or with the vomer." Elliot Coues, 1884

Common Fowl Skull

"Schizognathous skull of common fowl, nat. size, from nature, by Dr. R.W. Shufeldt, U.S.A. Letters as…