Kir«.—Botany and Conchology of Great Omaha. 363 
robust and tenacious of our introduced plants have not established themselves 
there. The few individuals which we find, appear there as intruders which do 
not flourish, but exist as it were by sufferance. They would probably die out 
altogether were it not that neighbouring cultivations serve as centres of 
propagation. As a matter of fact, the high road alone divides the area on 
which I collected from another which has for a long time been under cultiva- 
tion and sown with English grasses, and even in the very midst of the former 
there existed at the time a paddock which had been twice ploughed, and was 
then under a crop of oats. 
Art. L.—On the Botany and Conchology of Great Omaha. 
By T. KiE FLE 
[Read before the Auckland Institute, 23rd September, 1872.] 
Tue harbour of Great Omaha is about forty-five miles north of Auckland, 
lying nearly midway between Mahurangi and Pakiri. For the purposes of 
this paper the district may roughly be sketched as extending from the 
Matakana Falls to Little Omaha, the latter situate about eight miles from 
Point Rodney. 
The district is bounded on the west by the hills known as the Omaha 
or Pakiri ranges, which attain their greatest altitude, 1,380 feet, at Mount 
Hamilton, and are chiefly composed of sandstones overlying palzozoic slates, 
the latter often in a decomposed condition where exposed. 
An outlying range of no great altitude, extending from Mount Hamilton 
to the head of the Matakana River, may be considered the southern boundary, 
while the coast line from thence to Takatau Point, and inwards from the 
mouth of the harbour to Little Omaha, will form its eastern side. 
Dioritic rocks occur at the entrance to the harbour and other places. 
Fossil shells of several species are found at Kohuroa and Little Omaha ; 
amongst those collected in the latter locality is an immense Ostrea which 
exhibits singular and varied forms. The southern boundary is marked by a 
sharp conical peak of diorite which at once attracts the notice of the traveller 
from the contrast it offers to the rounded summits of the adjacent hills, 
From the base of the range, and extending to the inner waters of the harbour, 
is a considerable extent of flat land, much of it Swampy and intersected by 
numerous small streams. The inner waters are separated from the ocean by 
Whangatau, a peninsula of blown sand with a magnificent beach three miles 
in length and half a mile in width at low water. The entrance to the 
harbour is narrowed by a conical rock, which is exposed at half tide, but 
