168 JARSUPIALIA 
near its postero-external angle. Fourth upper premolar with a 
secant edge, and an inner basal ledge or tubercle ; corresponding 
lower tooth secant ; both may be longer or shorter than first molar. 
Molars (except very occasionally) with a distinct longitudinal bridge 
connecting transverse ridges. Lower incisors long and scalpriform, 
with inner secant edges opposable, owing to the loose articulation of 
the mandibular symphysis. 
This genus includes the true Kangaroos and Wallabies, the size 
of the individual existing species varying from that of a Rabbit 
to that of a Man. There are no less than twenty-three existing 
species, which may be divided into three groups, as well as many 
extinct ones. The genus is found in Australia and New Guinea, 
as well as in the eastern half of the Austro-Malayan transitional 
region. 
The first group, or true Kangaroos, comprises the largest 
existing forms, which are generally of a uniform and sombre colour. 
The skull is of a large and massive type, with the palate more 
or less well ossified posteriorly, while the molars frequently have 
a median longitudinal bridge connecting the first transverse ridge 
with the anterior talon, and no antero-external bridge between the 
same ridge and talon. The history of the discovery of the typical 
representative of this group, as being of considerable interest, may 
be given at some length. When Captain Cook, during his first 
memorable voyage of discovery, was detained for the purpose of 
refitting his ship at Endeavour river on the north-east coast of 
Australia, a strange-looking animal, entirely unknown to them, was 
frequently seen by the ship’s company; and it is recorded in the 
annals of the voyage that, on the 14th of July 1770, “Mr. Gore, 
who went out this day with his gun, had the good fortune to kill 
one of the animals which had been so much the subject of our 
speculation, . . . and which is called by the natives kanguroo,” a 
name which, though it does not appear to be now known to any of 
the aboriginal tribes of the country, has been adopted for ‘this 
animal in all European languages, with only slight modifications of 
spelling. With the exception of a passing glimpse in the beginning 
of the sume century by the Dutch traveller Bruyn of some living 
examples of an allied species, this was the first introduction to the 
civilised world of any member of a group of animals now so 
familiar. The affinities of the species, skins of which were brought. 
home by Captain Cook and subsequent voyagers, were recognised 
by Schreber as nearer to the American opossums (then the only 
known Marsupials) than to any other mammals with which zoologists 
were acquainted, and consequently it was placed by him, in. his 
great work on the Mammalia, then in the course of publication, in the 
genus Didelphys, with gigantes for a specific designation,x—the latter 
having heen bestowed upon it by Zimmermann under the impression 
