GEOLOGY OF ^^EW ZEALAND. 193 



by Dr. von Haast and by myself ; but Dr. Hector prefers the second 

 for the larger groups, giving local names only to the series. Of 

 course there is no real difference between the two methods, it is 

 merely a question of nomenclature ; but in a district so far from 

 Europe as is New Zealand, the second plan must for many years be 

 more or less uncertain, and constantly liable to change as our palse- 

 ontological knowledge increases ; and different geologists may call 

 the same group of rocks by different names. The first plan is not 

 open to this objection, and is, indeed, the same as that necessarily 

 employed in Europe. As geological investigation advances, other 

 systems and series may have to be added ; but those that are once 

 generally accepted remain for all time. 



It is on this first plan, therefore, that I propose to group our 

 rocks ; but as the method has as yet been applied only to separate 

 districts, many of the names used are synonymous, and it becomes 

 necessary to introduce a modified scheme applicable to the whole 

 of New Zealand. This I have attempted to do, and will state the 

 considerations that have guided me in drawing it up. In the first 

 place the names of the systems and series should be geographical, 

 and taken from the most typical districts, where the rocks are best 

 developed and contain the most fossils ; but names already in pretty 

 general use should not be altered, althongh some other locality 

 might logically furnish a better name. In the second place the 

 names of the systems and of the series should be of Maori origin, 

 in order that they may be characteristic, and may convey to geo- 

 logists in all parts of the world the idea that they belong to New 

 Zealand. In the third place, priority in nomenclature should be 

 allowed considerable weight. The following Table shows the ar- 

 rangement I propose. The right-hand column gives the probable 

 European equivalent, that is the probable age ; but it must be under- 

 stood that this is merely provisional and constantly liable to change. 

 I have introduced among the systems two new names — Hokanui 

 and Takaka, each of which represents a natural group of rocks to 

 which no collective name has previously been applied ; and yet names 

 are necessary, for in many parts of New Zealand we can refer rocks 

 to one or other of these systems, and yet, in the absence of fossils, 

 it is impossible to say to which series they belong. The grouping 

 of the Tertiary rocks is founded on that given in a former commu- 

 nication to the Society *, but it includes modifications subsequently 

 made. 



* " Synopsis of the younger Formations of New Zealand." Quart. Journ. 

 Geol. Soc. vol. xxix. p. 372. 



