ON THE EXTINCT ANIMALS OF THE COLONIES OF GREAT BRITAIN. 257 
langes in the same numbers, or according to the same formula, 
as the Mammalian paw. 
Detecting many and various modifications of this carnivorous 
reptilian type, I felt constrained to group them into a distinct 
order, called Theriodontia. , This order was exemplified in 
South Africa by a species and genus ( Titanosuchus ferox ) sur- 
passing the lion in size ; by others as large as a leopard ( Lyco - 
saurus pardalis ) ; and by others, again, as small as a cat or 
foumart ( Galesaurus and Procolophon). I may also note a fact 
of some significance, that the incisive formula in the Theriodonts 
is not that of the higher or placental Mammals, but of the 
lower, more reptilelike, marsupial ones. Thus, Cynodraco 
, . 5-5 
. has , 
4 - 4 ’ 
like the opossums ( Didelphis ) ; 
Lycosaurus has 
i 
4-4 
3 - 3 ’ 
like Tkylacinus and Sarcophilus (the native hyaena 
and devil of the Tasmanian colonists) ; while the placental 
. 3—3 
Carnivora never show more than i . 
3—3 
In the existing Reptilia the characters above specified are 
wanting. They would have been unknown and unsuspected as 
reptilian ones, save for such researches as are here summarized. 
If the gap in the series of animals continued from the Triassic 
to the present period had not been filled up otherwise than by 
reptiles, the living remnant of that class would have testified 
to total loss of such gains of organization as had enriched the 
predecessors of modern tortoises, lizards, and crocodiles. 
We now know, through discovery and study of fossil remains, 
that not one of the gains which benefited our extinct reptiles 
has been lost, but has been handed on, and advanced through a« 
higher type of vertebrates, of which mammalian type we trace 
the dawn back to the period when reptiles were at their best, 
grandest in bulk, most numerous in individuals, most varied in 
species, best endowed with kinds and powers of locomotion, and 
with instruments for obtaining and dealing with both animal 
and vegetable food. 
Then obtrudes the question, and will not be parried, Has the 
transference of structures from the Reptilian to the Mammalian 
type been a seeming one, delusive, due to accidental coincidences 
in animal species independently created ? Or, was the trans- 
ference real, consequent on the incoming of modified species by 
way of descent, and through the operation of a secondary law ? 
Certain it is that the lost reptilian structures defined in this 
paper are now manifested at the Cape of Grood Hope by quadru- 
peds with a higher condition of cerebral, circulatory, respiratory, 
and tegumentary systems. But into these higher generaliza- 
NEW SERIES, VOL. III. — NO. XI. S 
