Hemitrypus

Represented by a vertebra of the general character of those of the genus Scapherpeton, but which laeks the foramen chordae dorsalis of the posterior half of the centrum, and is not carinate on the inferior surface. The diapophysis is directed backwards just below the posterior zygapophysis, inclosing with it a notch into which the anterior zygapophysis is received. Anterior zygapophyses connected by a prolongation of the neural arch. I had suspected that this vertebra might be one of those of the cervical region of a species of Scapherpeton, hut the position of the foramen chordae dorsalis renders this highly improbable. The only position to which it could he assigned in the column of this genus would be that of the axis. But the foramen is present in the posterior half of the atlas and thus probably in the axis in Scapherpeton, as in vertebrae from all other regions of the column, so that such an exception as is presented by the present centrum is not to be locked for. The absence of the carina, and the cylindric form of the centrum, add to the belief that the species does not belong to Scapherpeton.