54 
Anomodontia . — Procolophonia and Dicynodontia. 
Wall-cases, 
Nos. 7, 9. 
Table-cases, 
Nos. 18, 19. 
Order XI.— ANOMODONTIA. 
Order Anomodontia. — In this order the body is lacertiform 
(lizard-like), and the limbs are adapted for walking. The 
sknll is comparatively short ; the quadrate bone is fixed ; a 
parietal foramen is present ; there are either one or two 
temporal arcades ; the nasals are large ; in the palate the 
pterygoids meet together in front of the basisphenoid, which 
they also join, but diverge anteriorly ; the palatine bones are 
small and placed internally to the pterygoids, as in Mammals, 
the dentition is thecodont (teeth placed in distinct sockets), but 
the teeth may be anchylosed to the bone. The vertebrae are 
amphiccnlous (concave at both ends), and in some cases they have 
notochordal centra (centra, gelatinous, unossified)* ; the dorsal 
vertebrae have long tranverse processes, and the anterior ribs 
articulate by double heads. Abdominal ribs seem generally to 
have been absent. In the Pectoral girdle an interclavicle, 
clavicles, and precoracoids are present, and a sternum was 
probably always developed. 
In the pelvis the pubis is placed in advance of the ischium to 
which it is completely united. The body of the ilium is in advance 
of the acetabulum. f i he tarsus has one centrale, and the phalangeal 
bones of the manus and pes are typically 2, 3, 3, 3, 3, in number 
as in Mammals ; the whole structure of the foot being Mammalian 
in type. . 4Y e are led to conclude, from recent researches, that 
these animals are directly descended from the Labyrintliodont 
Amphibians, more especially from the Arch aego saurian family, 
they are also related in all probability to Monotreme Mammals. 
This order appears to be confined to the Permian and Trias. 
Table-case, 
No. 19. 
Sub-order 1 . — Procolophonia. 
To the Anomodontia are now referred the small reptiles of 
the genus Procolophon , with a short triangular and somewhat 
depressed skull ; their dentition is carnivorous but the marginal 
teeth are all alike and are completely anchylosed to the bone ; 
teeth are also borne upon the vomer and the pterygoids! 
Procolophon presents many points of resemblance to Sphenodon 
and the Phynchosauridce. The genus is met with in the Karoo 
Beds (Trias), of South Africa. 
Dicynodon. 
Wall-case, 
No. 9. 
Table-case, 
No. 19. 
Sub-order 2.— Dicynodontia (Double Dog-toothed). 
Family Dictnodontid2E.— The Dicynodontsf are a very 
peculiar family of reptiles from the Trias of South Africa. 
The circumference of the centrum is in some species ossified so as to 
form a bony tube, while the centre remains gelatinous. 
+ The genus, Dicynodon, is so called from Sia, two, and kvvoZoq, canine 
tooth, Irom the two tusk-like canines in the upper jaw. 
