224 
PROFESSOR H. G. SEELEY ON THE STRUCTURE, ORGANIZATION, 
show one foramen without indicating the other. There is no reason to suppose that 
all Anomodonts have a radial as well as an ulnar foramen, for the external foramen 
is certainly absent in Galesaurus ; but, when only one foramen is seen, its direction 
appeal's to be transverse, and it passes obliquely from the ulnar to the radial side. 
On referring to drawings which I made in the Senckenberg Museum, at Frankfort-on- 
the-Main, in 1878, of some fragments of humeri which were described by voN Meyer, 
and have since been regarded as European Theriodonts by Sir Pt. Owen, I find both 
foramina present, though the radial foramen is relatively small in Brithopus. 
The ecto-pterygoid bone is stated by Sir R. Owen to cease to exist in both 
Theriodonts and Dicynodonts; and this bone never reappears in the Mammalian 
series. But two specimens in the British Museum suggest doubt whether the bone 
is absent, or hidden by the pterygoid. Sir R. Owen also finds in Iguanodon, 
Scelidosaurus, and Pm'eiasaurus dental characters which reappear in certain 
Mammalia, such as the Sloth and Kangaroo. He finds the number of incisors in 
these fossil Reptiles to be closely comparable with Marsupials. Thus, Didelphis and 
Cynodraco have the formula i -r^ ; and in Thylacinus, Sarcophilus, and Cynochampsa 
■i , 4 
. .4.4 
it IS ^ ' 
o. 6 
This memoir was succeeded by two papers* upon Platijpodosaurus rohustus. The 
vertebrae are said to differ from those of Kistece 2 )halus and Anthodon in the less depth 
of the terminal concavities, in which character they approach Dicynodon and Ouden- 
odon; but among the Plesiosauria this character is very variable, and seems to me a 
specific rather than a generic difference. The author compares this vertebral condi¬ 
tion to that found in Echidna, but I do not find the resemblance close enouD-h for 
comparison. An element of the sternum is recognized as the foremost sterneber, and 
identified with the first sternal element in Ornituorhynchus and the sternum of 
modern Lizards; and this bone is inferred to have been one of a series such as is" 
present in Chameleons and Bkinks. Its upper border is thought to have joined the 
coracoid, as in Monotremes, while its lower border may have given attachment to 
sternal ribs. The scapula is intermediate between that attributed to Dicynodon and 
the scajiula of Kisteceplialus. The nearest resemblance to the humerus is found in 
Ornithorhynchus and Echidna, On the digits it is remarked that the ungual 
phalanges, though relatively shorter, have more the proportions of those of Echidna 
than of Ornithorhynchus. What remains of the femur is compared with the proximal 
part of the bone in Echidna. The sacrum is said to be more Mammalian than that of 
Dicynodon, and to come nearer in shape - to the Megatherioid Mammals. The 
hlammalian character is considered to be mai'ked by the breadth of the iliac bones, 
and the extent of the confluence of the similarly expanded ischia and pubes, and by 
their confluence at the ischio-pubic symphysis. 
* ‘ Geot Soc. Quart. Journ.,’ vol. oG, p. 414, 1880; and vol. 37, p. 266, 1881. 
