370 Transactions. — Botany. 



dug into, moisture from all sides flows into the newly-made 

 cavity. At the bottoms of the mutton-birds' holes, too, water 

 must sometimes lie.* 



At the southern extremity of the northern island is the 

 remains of an old beach, or river- terrace, built up of rounded 

 stones firmly cemented together, none of which contain lime. 

 This formation Mr. G. J. Roberts, Chief Surveyor for West- 

 land, informs me is of glacial origin, and corresponds to similar 

 deposits on the mainland. 



Both islands are densely covered with vegetation, and the 

 flat rocks mentioned above contain many deep pools in which 

 seaweeds are abundant, while the rocks themselves are thickly 

 covered with Hormosira banksii. 



2. Vegetation of the Larger Island. 

 (a.) Plants of Bocks. 



The richness of plant life on the rocks depends chiefly on 

 their position with regard to sun and wind, and upon the steep- 

 ness of the rock-face. Where the cliffs are in the shade, and 

 consequently always more or less wet, they are densely clothed 

 with vegetation ; but in other places the plant-formation is 

 an open one, the plants occurring in larger or smaller patches, 

 while in others again the rocks are bare, except for lichens. 

 Over the top of the precipices! facing the mainland hangs 

 Veronica elliptica. Below this belt is frequently a zone of 

 Asplenium obtusatum, beneath which are long vertical breadths 

 of Tillcea moschata and Lepidium oleraceum mixed together. 

 Samolus re-pens occurs on the drier portions of the rocks, occupy- 

 ing crevices, and thus sometimes making long lines more than 

 2 m. in length and some 17 cm. in breadth. Finally, in some 

 places the thick-leaved fern Lomaria dura grows more or less 

 luxuriantly. 



On the flat rocks at the northern end of the island are Samo- 

 lus repens, Apium prostratum, Scirpus nodosus, young plants of 

 Veronica elliptica, Phormium tenax at the margin of the rocks 

 coming almost to the water's edge, and in some places are masses 

 of Rumex flexuosus with shoots attaining a length of + 1 m. 



(b.) Zonal Distribution of Plants on Surface of Island. 

 As seen from the above description of rock-vegetation, the 

 distribution is in part zonal, but the surface of the island, espe- 



* This is the station where the leech recently described by Dr. W. B. 

 Benhain under the name Hirudo antipodum was discovered by Mr. W. 

 Dnnlop anil myself. (Sec Trans. X.Z. Inst., vol. xxxvi.. p. L85, 1904.) 



t Here is the breeding-ground of the spotted shag {PhcHacrocorax 

 punctatus), large numbers of young being on the cliffs and adjacent rocks 

 at the time of our visit. 



