280 
PROFESSOR H. G. SEELEY OR THE STRUCTURE, ORGANIZATION, 
is much narrower'than in Dicynodouts, and rather suggests Placodoiits. There is a 
vertical median ridge above the summit of the foramen magnum. On the other side 
of tlie specimen there is an impression of that ex-occipital process which extends 
transversely outward, and gives attachment to the lower part of the squamosal. The 
impression was evidently due to a squamous bone being lost from it, and I can only 
surmise that tlie missing element may have been the quadrate; but such a relation of 
the cjuadrate is never found in any Dicynodont, The impression of the lateral border 
of the cerebral cavity is seen, and appears to have been relatively wider than in South 
African Peptiles. The large foramen for the fifth and other nerves is partly defined, 
and the ali-sphenoid, which bounds it in front, ascends as a slender process. Between 
the ali-sphenoids the brain cavity contracts. There is a median excavation for its fioor 
in the basi-sphenoid. Anteriorly the basi-sphenoid terminates in a lai'ge transv'erse 
sutural facet. There are thus conspicuous resemblances of this occipital plate to the 
bone figured in this memoir, it. 1021, and differences which show it to have belonged 
to another generic type of the same order. A single vertebra is figured by vox 
Meyer. Its neural arch rather suggests Nothosaurs, while the cupped form of the 
body is Plesiosaurian. The vertebra appears to be dorsal, and the rib articulates by 
two heads, but narrowly separated from each other, rather suggesting the Plesio¬ 
saurian than the Ichthyosaurian type, but making a transition from the double¬ 
headed anterior dorsal rib type of Pareiasaiirus to the single-headed dorsal type of 
Plesiosaurus. The scapular arch is instructive, although the hones are imperfect. It 
was formed by the scapula and coracoid and pre-coracoid. The pre-coracoid is a 
comparatively large bone, which extends to the margin of the articular surface for the 
humerus. It is perforated by the usual foramen, which passes obliquely forward, so 
that on the internal surface it excavates the margin of the scapula, in the way seen 
in Dicijnodon. Other specimens show the scapula as a strong compressed plate of 
somewhat Dinosaurian form, but not dissimilar to types of scapulae from South Africa. 
The humerus has the radial crest moderately developed, and has a rather more 
slender shaft than is usual in the Dicynodont family, though more slender bones are 
known. The pelvis is remarkable for the way in which the ilium contracts above the 
acetabulum, and for the narrow superior facet in the acetabulum for articulation with 
the femur. It more suggests Phocosaurus than any Dicynodont; and the obfurator 
foramen has a similar oblique passage through the bone, extending forv^'a]’d towards 
the pubic border. The narrowing of the superior mass of the ilium may be profitably 
compared with the spatulate condition of the attached end of the ilium in Plesio¬ 
saurus (as well as with the reduced dimensions of the bone in Nothosaurus). The 
expanded forms of the pubis and ischium are intermediate in character, as in mode 
of union, between the conditions of those bones in Plesiosaurs, Nothosaurs, and 
Ichthyosaurs. A proximal end of an ulna is figured by von Meyer, which is 
interesting as showing not only similar form to that seen in South African Dicyn- 
odonts, but it also gives evidence that the bone dev'eloped an epiphysis or olecranon 
