. Revision of the Amphibia and Pisces of the Permian of North America. .—Trimtrorhaehis insignis. No. 4557 Am. Mus. A. Top view of a skull. X f. B. Another skul! carrying same number as that shown in A, showing such sutures as can be made out. X f. Lettering as usual. C. Lower view of same skull shown in B. X f. pt, pterygoid. D. Lower surface of skull shown in A. X yi. pt, pterygoid; pa, parasphenoid. the lower surface the elongate parasphenoid joins a well-formed basioccipi-tal, which bears a single, oval occipital condyle with a concave, articularface. The pterygoids send processes inwards
. Revision of the Amphibia and Pisces of the Permian of North America. .—Trimtrorhaehis insignis. No. 4557 Am. Mus. A. Top view of a skull. X f. B. Another skul! carrying same number as that shown in A, showing such sutures as can be made out. X f. Lettering as usual. C. Lower view of same skull shown in B. X f. pt, pterygoid. D. Lower surface of skull shown in A. X yi. pt, pterygoid; pa, parasphenoid. the lower surface the elongate parasphenoid joins a well-formed basioccipi-tal, which bears a single, oval occipital condyle with a concave, articularface. The pterygoids send processes inwards to join the parasphenoid, andbackward to the quadrate region. The anterior processes of the pterygoidare very narrow, with concave inner edges, leaving very large palatal vacui-ties. The posterior portion of parasphenoid and the pterygoids are coveredwith fine teeth. In two specimens, considered by Cope as T. insignis, there is consider-able difference in the parasphenoid and basioccipital bones. In No. 4565, io8 AMPHIBIA AND PISCES OF THE PERMIAN OF NORTH AMERICA. 37.—T. insignis. Outline of base of skull. No. 4565 Am. Mus. X !•Cross-section of occipital condyle of of base of skull. No. 4557 Am. Mus. X of occipital condyle of same. the type, the sides of the posterior part of the parasphenoid are much moresharply cut out and the whole region is narrowed; the section of the occipitalcondyle is broadly heart-shaped. In No. 4557 the same region is muchbroader, and the section of the occipital condyle is a wide oval. It is pos-sible that these should bereckoned as distinct species,but it seems best to wait formore evidence. It is impossible to makeout the sutures between thebones in the anterior partof the palate. The internalnares are far forward, andthe palatine and prevomer-ine regions are covered withsmall teeth; there are notusks lower jaws are widely separated posteriorly, due to the width of theskull; they curve forwar
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Keywords: ., bookcentury1900, bookdecade1910, bookidc, booksubjectpaleontology
