168 Proceedings of the Royal Physical Society. 



make upon it, I shall adopt the comparisons made by Professor 

 Owen on the typical skull of the genus Palapteryx. The 

 breadth across the mastoid processes in the mutilated cranium 

 from Uotomarrama is 2 x 7 oth inches ; the length of the cranium, 

 measured from the upper part of the foramen magnum to the 

 anterior extremity of the frontal bone, is 3 X 3 ^ th inches ; the 

 breadth across the postorbital processes is 2 T %th inches; the 

 breadth across the temporal fossse is l T 7 oths of an inch. The 

 vertical diameter, from the supraoccipital ridge to the basi- 

 sphenoid, is l^ths of an inch. The transverse diameter of 

 the occipital foramen is nearly x 6 oths of an inch. The breadth 

 across the paroccipitals is 2\ inches. The sutures of the skull 

 are entirely obliterated ; and from the well marked muscular 

 impressions and rugose surface, there is no doubt that it be- 

 longed to an old bird. The occipital foramen is subcircular, 

 and broadest transversely ; the descending basioecipital is 

 impressed by a shallow pit, divided by a slight median ridge, 

 and bounded below by the straight posterior border of the 

 basisphenoid platform, the outer angles of which are large 

 round tuberosities. The precondyloid foramina are situated 

 at the upper and back part of the basi sphenoidal protuber- 

 ances, midway between the outer edge of the paroccipital ridge 

 and foramen magnum, and raised to a level with the lower 

 border of the occipital condyle. The precondyloid foramina 

 pass obliquely upwards and inwards into the cranium, and 

 there are two small pits at the inner and upper edge, nearer 

 the occipital condyle. The paroccipital ridges, partly broken 

 in this specimen, are of a semilunar form, and separated by a 

 notch from the basisphenoidal protuberances. The canal for 

 the carotid artery is seen grooving the sides of the sphenoidal 

 platform, winding round the outer part of the base of the 

 sphenoidal protuberances, penetrating the basisphenoid, just in 

 front of the lower edge of the paroccipital ridges, and entering 

 the cranium by the aperture common to the precondyloid 

 foramina internally. The occipital region is divided into two 

 parts by a broad median vertical ridge, with two strongly 

 marked depressions on each side ; but the subdivision, " slightly 

 indicated by the bending down of the supraoccipital ridge," 

 in Professor Owen's description of P. gerenoides, is not 



