270 
POPULAR SCIENCE REVIEW. 
his poultry-yard, it is not likely that either species would have 
escaped the notice of the Australian settler if it had lingered 
on to be a pest, or an ally, to any of the great Colonies of that 
continent. 
I conclude, therefore, that both the species have become 
extinct in Australia, and that they formerly existed there as 
they still exist in Tasmania. Moreover, in addition to the 
cave specimens, I have received evidences of both Thylacinus 
and Sarcophilus from the drift deposits and beds of rivers in 
several and distant parts of Australia. And these fossils, 
besides testifying to species undistinguishable by tooth and 
bone from the Tasmanian kinds, indicate others of larger size, 
which have never been observed living. Of Sarcophilus , of 
which the present ursine kind might be matched by a jackal, I 
have had evidence of a species ( Sarcophilus laniarius) as big 
as a leopard. Of Thylacinus I have also fossils of a larger than 
the existing kind, equalling a panther in power ( Thylacinus 
major'). Neither of these extinct Australian carnivores, how- 
ever, bore the proportion to the nototheres and diprotodons 
which the South African lion bears to the buffaloes, elands, and 
other great herbivores upon which it preys. 
Something still seemed wanting in the proportion of the 
beasts of prey to the beasts which converted the grass and 
herbage of the field into flesh in these ancient epochs of Aus- 
tralian life. 
Now, among the fossils submitted to me by Major Mitchell, 
in 1835, was a tooth which, from its resemblance to that called 
the “ carnassial ” or “flesh-cutter” in the lion’s jaw, raised a 
suspicion that there had existed in Australia a carnivore ex- 
ceeding in size the largest of the extinct Thylacines. But a 
comparison of this solitary fossil with all the modifications of 
the teeth in the various existing kinds of Marsupialia, had 
made me acquainted with a somewhat similarly shaped sectorial 
tooth in certain small phytophagous and mixed-feeding genera. 
I could not, therefore, give undue weight to other resemblances 
supporting only a conjecture. Additional discoveries might 
supply the required test, and were to be waited for. If the 
large fossil sectorial tooth in question was the premolar of a 
gigantic phalanger or potoroo, it must have been preceded by 
teeth shaped for cutting and nibbling, and have been followed 
by several large flat or ridged broad molars for crushing and 
grinding. If the large sectorial tooth was a premolar of a 
carnivore, it must have been preceded by teeth for piercing and 
holding, and have been followed by molars small in size and 
few in number, tubercular in shape, and adapted at best for 
pounding gristle or tendon. 
Pending, therefore, the possible acquisition of specimens 
