PRESIDENT’S ADDRESS. 339 
characteristic of the Ethiopian region. In both these con- 
tinents, the southern forms met the northern immigrants, 
so that both these regions present a peculiar admixture of 
forms. But, be it noted that, both in South America and 
South Africa, the more archaic genera persisted in the 
extreme southern area. 
In New Zealand, the Acanthodrilids have met with no 
competition from Northern forms; the original inhabitants 
have been fairly prolific in giving rise to a number of 
genera, but they are all very closely allied. This indi- 
cates an early and persistent isolation, such as we have 
learnt to consider as an established fact from geological and 
biological researches. 
The earthworm fauna of New.Zealand is not only a very 
. homogeneous fauna, but it is very ancient—far older than 
that of Australia; indeed, in its entirety, the oldest in the 
world. 
Let us now consider Australia, for it presents us with 
several rather perplexing problems. The Acanthodrilids 
appear to have entered the continent, and may have spread 
over practically the entire land at a time when conditions 
permitted, which must have been, according to Spencer and 
others, not later than mid-Tertiary times, before the central 
region, at any rate, was as dry as at present. 
It will be remembered that the only earthworm found by 
the naturalists of the Horn Expedition was a species of 
Notiodrilus, specimens of which were found on three moun- 
tain ranges—George Gill, McDonnell, and James Ranges— 
separated by desert. Spencer pointed out that probably 
this worm—“ the sole survivor of the old earthworm fauna, 
which almost disappeared when in post-Pliocene, the climate 
changed ’—was a member of an ancient genus, which had 
once been widely spread over the continent; and he sug- 
gested that it had entered from New Zealand by the north- 
east connection, as far back as.the lower Cretaceous. 
The absence of any Acanthodnlid in Papuan Land, and 
in the northern islands of the ‘“‘ Melanesiarr Plateau,” seems 
at first sight to negative this northern entry of Acantho- 
drilids. It is, however, a curious fact. that the three other 
Australian species of Votiodrilus occur in the northern por- 
tion of the continent—two of which are in Queensland— 
whereas, in South Africa and South America, the ancestral 
and original settlers persist in the south, and their offspring 
have migrated northwards. In other words, in those two 
continents the more archaic worms persist near the point of 
