Hurron.—Cause of former Extension of Glaciers in New Zealand, 385 
bring it to between 8,000 and 4,000 feet, which. is about the amount esti- 
mated in a different way by Mr. Dobson. This estimate I am willing to 
adopt, for, since my examination of the province of Otago, I think it more 
correct than my previous one. 
Now the mean annual temperature of the following places is as under :— 
an Ann : 
. acentben oad Latitude. 
Monganui .. ae whe as 60-1 B5-1 
Auckland ., + és ne 59°5 35-50 
Wellington .. ae wa es 555 41°16 
Dunedin rg = ae be 50°7 45°52 
Invercargill .. ae i ‘a 50°3 46°17 
And, if we take the mean annual temperature of the snow line to be 82° 
¥’., this will give a decrease of 1° F., in temperature for every 863 feet in 
altitude at Auckland, 353 feet at Wellington, and 874 feet at Dunedin. I 
will therefore adopt a mean of 868 feet for New Zealand. 
From this it follows that a reduction of the temperature of Wellington 
to that of Dunedin would be equivalent to an elevation of 1742 feet, a 
reduction of the temperature of Auckland to that of Dunedin would be 
equivalent to an elevation of 3,194 feet, while the reduction of the tempera- 
ture of Monganui to that of Invercargill would be equivalent to an elevation 
of 8,857 feet. So that in order to bring back the former extension 
of the glaciers, by change of climate alone, the mean temperature at 
Monganui would have to be reduced below the present mean temperature of 
Invereargill—that is to say, the whole climate of New Zealand would have 
to be reduced by more than 10° F. 
Now in the pleistocene beds of Wanganui, Motarau, and Oamaru we 
find the following species of recent shells, none of which are as yet known 
to extend as far south as the coasts of Otago.* 
Big Big 
ae ae 
ais gis|a 
ei alo E|a\/9° 
Dentalium seta * stecttveaied eye * 
Murex octo ee Ss Crypta torta Te hota a 
rophon pavia A Soh Moniles: aii * 
Fusus zealandicus * Pholadidea wie + 
: », triton ; “ ia acinaces * 
5, nodosus % Venus zealandica ei 
= ees * Chione yatei... ~ 
Cominella virgata * || Callista disrupta ‘ 
Cassis pyrum AS Mysia zealandica * 
* Future research will no doubt reduce this list but it is not likely to — affect 
the argument. 
