THE FALKLAND ISLANDS. 
431 
fannistic relationship with western North America, but this 
affinity seems to be confined to very ancient groups of verte¬ 
brates and invertebrates. I ventured to allude to the North 
American porcupines as being possibly the descendants of 
Steiromys, which I suggested had utilised the early Tertiary 
land connection from Chile to Mexico or California. Stei¬ 
romys, however, is long since extinct. If we suppose the 
coyotes to have taken advantage of that land connection in 
early Tertiary times, we might assume a member of that early 
fauna to have succeeded in surviving in these lonely islands 
until recent times. But the difficulty in accepting such an 
hypothesis is that it would give the coyotes a much longer 
ancestry than any palaeontologist would care to admit. Never¬ 
theless it is the only theory I can suggest. Another question 
that occurs to me is—If the wolf was the only mammal in¬ 
habiting the Falkland islands, what did it live on ? Wolves are 
carnivorous, as everyone knows, usually feeding on smaller 
mammals. Yet Darwin states that it is the only quadruped 
native to the islands ; he adds, however, in a footnote, “ I have 
reason to suspect there is also a field mouse.” This is probably 
a species of Reithrodon or some allied genus. Still this 
mouse-like creature could scarcely have constituted the sole 
food of such a large animal as the wolf. In all likelihood, 
some larger rodent existed on the islands and may have 
become extinct before the advent of man. The wolf soon after 
this event shared the same fate. 
An examination of the earthworm fauna, which is probably 
of very great antiquity, reveals the fact that there are living 
on the Falkland islands two species of the genus Noteo- 
drilus (N. bovei and N. falclandicus) which otherwise is con¬ 
fined to South and Central America, New Zealand, Australia, 
Cape of Good Hope, Madagascar and several of the antarctic 
islands. A second genus, viz., Chilota, which is represented on 
the Falkland islands by Chilota daleti, inhabits only southern 
South America and the Cape of Good Hope, with the exception 
of a single species living on the Cape Verd islands. The third 
genus, Yagansia, has not yet been found on the Falkland 
islands. It is almost peculiar to Chile and Argentina. Only 
one species of Yagansia has been met with in South Africa.* 
* Michaelsen, W., “ Verbreitung d. Oligochaeten,” p. 74. 
