Cope, Geol. Surv. Ohio, II, pt. II, p. 370, pl. xlii, fig. 1; pl. xliv, fig. 2, 1875.
Cope, Proc. Phila. Acad. Nat. Sci., p. 16, 1875.
Moodie, Proc. U. S. Nat. Mus., 37, p. 27, 1909.
Type: Pleuroptyx clavatus Cope.
The specimens on which the species of this genus repose do not exhibit crania. The 5, probably 6, specimens which represent them offer various views of the vertebral column, and in none is there any trace of ventral or thoracic armature. Limbs can be ascribed to them with probability only. The vertebræ are of moderate length, with well-developed zygapophyses, and a short and not very elevated neural spine in the dorsal region, which is not sculptured in any way. The generic character is seen in the ribs. These are rather short and very stout and support an ala on the posterior or convex border, which expands downwards, and then suddenly contracts to the shaft. The extremity of the latter is broad and truncate, and includes a medullary cavity, which is only partially fitted with cancellated tissue.
Pleuroptyx clavatus Cope.
Cope, Geol. Surv. Ohio, II, pt. II, p. 370, pl. xlii, fig. 1; pl. xliv, fig. 2, 1875.
Cope, Proc. Phila. Acad. Nat. Sci., p. 16. 1875.
Moodie, Proc. U. S. Nat. Mus., 37, p. 27, 1909.
Type: Specimen No. 8617 G, American Museum of Natural History.