PROCOLOPHON FROM THE CAPE COLONY. 799 



malar bone the vertical narrow quadrate bone is attached; it is 

 nearly ^ inch in length, and sends inward and forward a large 

 thin process similar to that of Hatteria and of Dinosaurs. Upon 

 the quadrate bone appears to be a plate of bone (regarded by Prof. 

 Owen as the squamosal), which I am inclined to regard as the 

 quadrato-jugal ; it extends chiefly behind the quadrate bone. 

 Posterior to the quadrate bone the cranium is contracted a little, 

 and probably excavated in the auditory region. The rami of the 

 lower jaw are loosely adherent, and have a narrow union ; they are 

 straight, and diverge at a considerable angle. There are ten teeth 

 in each ramus ; the teeth in front are longer and more slender than 

 those behind, as in many lizards. Immediately behind the teeth is 

 a moderate coronoid process, and behind this the jaw thickens con- 

 siderably from side to side, so as to extend outward somewhat after 

 the manner of the lower jaw in some rodents. In the articular 

 region the lower jaw is inflected a little, so as to widen the articu- 

 lation. The extreme length of the lower jaw is 1 T ^ inch, but it 

 extends a little behind the quadrate bone and terminates in a rounded 

 and contracted heel. The depth of the jaw increases slowly from 

 before backward, but where deepest is not more than T 3 F inch at the 

 coronoid eminence. The cervical vertebrae remain attached to the 

 specimen, and are partly exposed by a fracture, so as to show indi- 

 cations of four or five. The centrums are rather short ; the articular 

 surface of the last is concavely or conically cupped with a central 

 notochordal depression or perforation similar to that figured by 

 Prof. Owen as Dinosaurian in Quart. Journ. Geol. Soc. vol. xxxii. 

 pi. v., but which is paralleled in Hatteria, as well as in Amphi- 

 bians and fishes. The neural spine of the first vertebra exposed 

 is expanded from front to back, and the neural spines of the 

 succeeding vertebrae are strong and directed backward as in Hat- 

 teria ; short transverse processes are given off on a level with 

 the base of the neural canal. To these processes slender cervical 

 ribs were attached ; but there is no evidence as to whether the arti- 

 culation was single or double. The vertebrae are bent at a right 

 angle with the roof of the skull, as in many mammals, ornithosaurs, 

 and other animals. Below the vertebrae, and behind the lower jaw, 

 is a portion of a thin expanded plate of bone, which is probably part 

 of the sternum, in front of which are fragments of long bones, too 

 imperfect for determination. As compared with Procolophon trigo- 

 niceps of Prof. Owen, which is of similar size, this species has the 

 head much more compressed from side to side, more elongated in 

 front of the orbits, has the parietal foramen smaller, and shows 

 various minor differences which are more easily gathered from a 

 figure than from description. 

 Procolophon cttneiceps, Seeley. (PI. XXXII. figs. 7, 8.) 



The second skull is somewhat larger and deeper, and the modifi- 

 cation of the malar arch is so different from that seen in the first 

 specimen, and in those figured by Professor Owen, as to leave no 

 reasonable doubt that the animal is specifically distinct ; and so, 



