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POPULAR SCIENCE REVIEW. 
In the Trias of Europe had been found the jaws and portions 
of skull of a fossil creature provided with large flattened crush- 
ing teeth, like a pavement covering the palate above, and the 
correspondingly broad tracts of the under-jaw. These fossils were 
referred by Agassiz and H. von Meyer to a supposed extinct fish 
Placodus, The first specimen of this rare genus that came to 
my hands, from Germany, showed, however, characters which 
led me to think it was a reptile, not a fish. It was with much 
pleasure, therefore, that I found among the Cape fossils an un- 
equivocal and larger extinct reptile, provided with similar 
crushing teeth, and with these only ; forming, likewise, a pave- 
ment upon the palate opposed to similar teeth on a broad 
alveolar tract of the lower jaw. Since describing and figuring 
this fossil, under the name Endothiodon , I have lately received 
a second species of the same genus, also from the Karoo beds. 
It is, of course, significant to note that the only analogous form 
of reptile from localities elsewhere than at the Cape had left its 
remains in deposits of Triassic age. At the present day, the 
only known aquatic vertebrates adapted by their teeth to crack 
and crush shell-fish belong to the class of Fishes: such, for 
example, are the Wolf-fish ( Anarrhichas ) and the Port Jack- 
son Shark ( Gestracion ). 
An extensive series of Reptilia has been brought to light from 
the Cape fossiliferous beds above specified, which were of a more 
strictly and decidedly carnivorous nature than the Dicynodonts, 
combining upper tusks of a more piercing and trenchant cha- 
racter opposed to a pair of similar tusks below, crossing in front 
of the upper pair when the mouth was shut. These killing 
and holding teeth, like the canines, or laniary teeth, of the lion 
and dog, were preceded by incisor teeth of a similarly pointed 
shape, and followed by molar teeth, of the character of those 
called carnassial or sectorial in Mammalian ferse. This type of 
dentition, in which the “ incisors,” “ canines,” and “ molars ” 
can be specified on characters of size, shape, and relative posi- 
tion, had hitherto been unknown, save in the Mammalian class ; 
but it is combined in these extinct Cape creatures with a true 
reptilian or cold-blooded cranial and vertebral structure. With 
this guiding evidence of the reptilian class of our present series 
of fossils, I farther found, associated with such dentition, that the 
teeth were retained, as in Mammals, sufficiently long for the 
fangs to dwindle and become consolidated at the implanted end ; 
that the humerus, with ridges and processes adapted to as free 
evolutions of the fore-paw as in the lion, also showed a canal 
for the passage and defence of a brachial artery and nerve, not 
present in any existing kind of Reptile, but characterizing the 
humerus in many, especially feline, carnivorous Mammalia. 
Furthermore, that the paws were supported by joints or pha- 
