. Revision of the Amphibia and Pisces of the Permian of North America. ewhat pentagonal outline. At the anterior angle is a tube-likeprojection from the edges of the neural canal, which fits into the foramenmagnum. The faces for the occipital condyles are elongate oval, and lookoutward and slightly upward. The neural spine is very broad and low. Itbifurcates posteriorly, sending back processes which reach nearly across thesecond vertebra and embrace its spine. A small process on the anterior endof the spine of the second vertebra fits into a notch at the point of bifur-cation of the first spin
. Revision of the Amphibia and Pisces of the Permian of North America. ewhat pentagonal outline. At the anterior angle is a tube-likeprojection from the edges of the neural canal, which fits into the foramenmagnum. The faces for the occipital condyles are elongate oval, and lookoutward and slightly upward. The neural spine is very broad and low. Itbifurcates posteriorly, sending back processes which reach nearly across thesecond vertebra and embrace its spine. A small process on the anterior endof the spine of the second vertebra fits into a notch at the point of bifur-cation of the first spine. The posterior zygapophyses are well developedand between them is a strong zygantrum. On the lower surface is a broadkeel which is reduced in size anteriorly until it disappears near the anteriorend. There is no evidence of ribs attached to the first vertebra. The second vertebra (axis?) is quite short and fits very closely againstthe first. The low neural spine has a deep pit, such as occurs in all the dorsal 88 AMPHIBIA AND PISCES OF THE PERMIAN OF NORTH AMERICA. vertebrae, and is regarded as the possible attachment of a cartilaginousneural spine. The anterior and posterior zygapophyses and the zygospheneand zygantrum are well developed. There is a low keel on the lower surfacewhich is somewhat broadened at the anterior and posterior ends. On thesides are two well-developed processes for the double-headed ribs; the loweris attached to the centrum and the upper to the neural arch. From this point the dorsal vertebrae are quite similar. The centrumis elongate with the lower surface concave antero-posteriorly, and in the large specimens nearly flat from side toside near the middle. In smaller speci-mens the lower surface is convex fromside to side. There is no trace of a keelon the centrum after the second ver-tebra. The neural spine is heavy andlow, with a deep pit, possibly for theattachment of a cartilaginous spine. Inthe American Museum specimen. , the processes for
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Keywords: ., bookcentury1900, bookdecade1910, bookidc, booksubjectpaleontology
