On Delphinognathus conocephalus (Seeley) from the Middle Karoo Beds, Cape Colony, preserved in the South African Museum, Capetown

Abstract

The skull herein described is the only portion of the animal collected. No locality for it is recorded in the South African Museum, but Mr. Thomas Bain, the Government geologist in Cape Colony, believes it to have been collected by himself from near Beaufort West. It is slightly distorted with the folding of the strata. The preservation of the specimen leaves something to be desired, for the pre-orbital region is more or less obscured by weathering, which has destroyed the superior contour of the snout, the alveolar border, and the anterior extremity of the jaws. The occipital condyle and much of the occipital plate from the back of the skull are also lost. But, notwithstanding these defects, the skull is the most interesting Anomodont preserved in Cape Colony, and indicates a new family of fossil Reptilia. The head is characterized by its broad, high, vertical occipital plate. The broad subpentagonal roof to the brain-case (fig. 2) ascends laterally from the inclined temporal region, and is elevated in a cone, which terminates in a large, circular, crater-like parietal foramen. The skull has large sub-circular vertical orbits, placed far backward above the hinder extremity of the lower jaw, so as to converge forward. The temporal fossæ are short and small, owing to the position of the orbits and the width of the cerebral region. The quadrato-squamosal region is directed obliquely forward, and forms a vertical articular surface to articulate with the lower jaw, which is singularly deep posteriorly, and suggests the jaw