Kirk. — On the Lake District of the North Island. 341 



Zoysia pungens, Willd. — Taupo plains, and about all the lakes. 

 Bromus arenarius, Lab, — Rotorua. 



Foa austraUs, Br., var. Icevis. — In all tlie low vallies from Te Ngae south- 

 wa-rds, bnt nowliere found on the hills above 1,600 feet. 



Zoysia pungens and Poa. Icevis are the only forms found over extensive 

 areas ', the propriety of considering the latter to be a littoral plant may 

 possibly be questioned by those who are familiar with its distribution in the 

 South Island only. In the Korth Island it occurs almost exclusively by the 

 sea, or by tidal rivers, as at Port Waikato, except when under similar circum- 

 stances to those now under consideration, as at Cambridge in the Middle 

 Waikato, from which locality it has been carried by the river to a recently 

 formed island at Kangiriri, as I learn from a specimen given me by Captain 

 F, W. Hutton. Mr. Buchanan informs me that in several instances in the 

 South Island it distinctly marks the margins of ancient sea basins. 



The examination of the southern and western parts of the district is 

 necessary to the full consideration of this interesting subject. 



It is worthy of remark that Rotokakahi and the Tikitapu Lake are the 

 only lakes at which littoral plants were not collected. These are situate at an 

 elevation of about 1,400 feet, or 300 feet higher than Lake Tarawera, and 

 nearly 200 feet above Lake Taupo. This points to the greater age of the 

 first-named lakes, and accounts for the absence of maritime plants on their 

 shores. 



The contrast between the arboreal vegetation of Rotokakahi and Roto- 

 tarawera is most striking, and from the short distance that separates the two 

 lakes is at once realized by the traveller. The most prominent trees on the 

 banks of the former are terrestrial specimens of Metrosideros rohusta, marked 

 by small, compact, uniform, green-tinted foliage ; on the latter, M. tomentosa, 

 with spreading tortuous arms, and bold, grey, many-tinted foliage, changing 

 with every breath of wind, — the one a plant specially characteristic of inland 

 forests, the other equally characteristic of the northern cliffs and sea beaches. 



Summary. 



For convenience of reference, I have prepared the following brief summary 

 of the additions to our phyto-geographical knowledge comprised in this 

 paper : — 



Clematis colensoi, Hook, f — Sparingly in earthquake fissures in the Wai- 

 horepa valley, the most northern locality known to me. 



Montia/ontana, L. — Attains its northern limit at Kaitiriria ; altitude 1,500 

 feet. 



Elatine americana, Arnott. — Exhibits an extension of its known range east- 

 ward at Maketu, and southward at Rotorua. 



