_Kirx.—Botany and Conchology of Great Omaha. 365 
certain seasons. In 1863 it was growing near the mouth of the harbour in a 
eculiar: manner, the blown sand gathering about the plant formed little 
hummocks through which the branches pushed their way to the surface, so 
that at a short distance the low white mounds appeared dotted over with 
green rosettes. A change in the outline of the beach in 1864 destroyed the 
plant in this part, and I have only seen it at the further end of the beach 
during recent visits. About the middle of the beach, but far back from high 
water-mark, is a clump of noble specimens of the pohutukawa and the tarata 
(Pittosporum erassifolivm) which doubtless mark the site of the old margin. 
A peculiar variety of Carex raoulii has arched and procumbent culms some- 
times more than six feet in length, and accompanies a slender sub-erect form 
of Pratia angulata. 
e preceding sketch of the chief physical characteristics of the district, and 
of the more prominent features of its vegetation, although very far indeed 
from being complete, is yet sufficient to show that the district is well adapted 
to support a large variety of molluscous life, and such is found to be the 
case. The enumeration at the close of this paper is not offered as a complete 
account of the shells to be found within its boundaries, but is the result of a 
cursory examination made nine or ten years ago, supplemented by a few 
species collected during recent visits, and especially by additions made by 
Mr. Charles Matthews, who is well acquainted with the plants and shells of 
the district, and to whom I take this opportunity of acknowledging my 
indebtedness for many rare specimens and much valuable information relative 
to habitats, ete. 
The beach at Whangatau is exposed to the force of north-east gales, after 
which high water-mark is fringed with large specimens of Turbo cookii, Pectun- 
culus laticostatus, Struthiolaria papulosa, Cassis pyrum, Pecten laticostatus, 
with more rarely the tine Triton australis and others. Spirula peronii is 
washed or rather blown amongst the sand-hills in countless thousands, whilst 
the beautiful Janthina exigua, and numbers of smaller shells, mark the 
extreme limits of the waves. Still more rarely Imperator heliotropium and 
the large Janthina communis may be collected. Mactra discors and M. ven- 
tricosa are not uncommon, and may be procured by digging beyond low water- 
mark. In the calmest weather, Mesodesma cuneata may be picked up between 
tide marks, and the common long pipi, M. chemnitzii, below low water-mark, 
Pecten laticostatus formerly occurred on a shoal accessible at neap tides, but 
the site is now covered by deep water, and the shell is found only after gales, 
The pretty P. zealandicus is frequently thrown on the beach, often associated 
with another interesting shell, Scalaria zelebori. Solenomya australis, the 
representative of the European razor-shells, with its periostraca produced 
beyond the margin of the shell, is often thrown up, but I never obtained 
