36 
anotlier to the Ganoids. The genus is now an inhabitant of 
the rivers of Queensland, where it also occurs fossil.* In 
Europe it is met with in the RhEetic series in the lower 
Mesozoic rocks, while in both Europe and America it is 
represented by the well-known Ctenodus of the Carboni- 
ferous period, as for example in the Ardwick Limestone. 
It is interesting to note that a genus in which so many 
characters now scattered through different orders are united 
should be of such high geological antiquity. It may fairly 
be viewed as an ancestral form of Mesozoic age which has 
found refuge in the fresh waters of Australia, while it has 
been banished from other parts of the world, and it now 
forms part of a fauna in which the Mesozoic trigonia, and 
the whole tribe of Cestraceont sharks are also represented by 
living types. 
3. Professor Oiven on a Neiu Order of Reptiles, 
I turn now to Palaeontology. New discoveries of singu- 
lar interest of intermediate reptilian and avian forms have 
been made both in the old and new worlds. The fossil 
remains of the Karoo lacustrine or brackish water rocks of 
South Africa, described by Professor Owen in February last 
[Quart. Journ. GeoL Soc., Lond., 126, 95], reveal the evi- 
dence of fossil reptiles of lower Mesozoic, or perhaps Permian 
age, which constitute a new order of ‘Theriodontia,’ the 
teeth being of the type of carnivorous mammals, and the 
incisors being defined by position, and divided from the 
^molars’ by a large laniariform canine in upper and lower 
jaws. The humerus, also, has a foramen on the inner side 
of the condyle unknown in any of the living reptilia, but 
appearing in certain of the mammalia. 
“In one (writes Professor Owen, p. 100), of the species of 
Saurians, with what is now the mammalian type of humerus 
and of dentition, evidence, for which I am indebted to the 
* Mr. Eamsay called my attention to a fossil palatal tooth of Ceratodus 
in the Australian Museum, Sydney, in 1875, 
