S. Attport — Nomenclature of Rocks. 583 



Professor M'Coy has also come to the conclusion that there was 

 no Glacial Epoch in Victoria. He says : " All our evidence, in fact, 

 goes to show that there was no Glacial Period in Victoria succeeded 

 by a warmer modern one, but that there has been a regular and 

 gradual falling of the temperature to the present day." 1 



In his " Geological Observations on South America," Mr. Darwin, 

 when mentioning any recent shells found fossil in the Pleistocene 

 beds of Patagonia and Chili, always states that the living forms are 

 found within a few miles of the fossil ones ; and never in any in- 

 stance does he mention them as belonging to species now living 

 further to the south. 



I have not seen the late Prof. Agassiz's account of his visit to 

 Patagonia, further than the short notice published in " Nature," but 

 I do not think that he procured any evidence of a northerly migra- 

 tion of the fauna in Pleistocene or Pliocene times, followed by a 

 southerly remigration ; nor even of glaciers having formerly entered 

 the sea in more northern latitudes than they do now. However, the 

 evidence, as far as South America is concerned, can be better studied 

 in England than in New Zealand, and the object of this paper is to 

 point out that there is no evidence whatever of a Glacial Epoch 

 having occurred in New Zealand, although, if it had occurred, there 

 is every reason to expect that it would have left sufficiently clear 

 traces behind it. 



I will also add that as New Zealand is nearly antipodal to Great 

 Britain, any change of climate in one place, caused by a change in 

 the position of the earth's axis of rotation, would also necessitate a 

 similar change in the other place. 



III. — On the Classification and Nomenclature of Eocks. 

 By S. Allpokt, F.G.S. 



IN the September Number of the Geol. Mag. pp. 425, 426, there 

 are some remarks by Mr. G. H. Kinahan on the nomenclature of 

 certain igneous rocks, on which I should like to offer a few observa- 

 tions. The rocks referred to belong to the acidic group, and are 

 mentioned under the various names of granite, nevadite, granitic 

 rhyolite, liparite, trachyte, elvanite, siliceous elvanite, felstone, 

 bottleite, trachalite ; the two last being synonymous, for it appears 

 that bottleite is the local name for a vitrioid rock pronounced to be 

 trachalite ; but several of the other names are also synonymous or 

 useless, for we are told that nevadite — a proposed new addition to 

 our granitic rocks — is characterized by a more or less crystalline 

 felsitic matrix inclosing crystals of quartz, one or two felspars with 

 mica or amphibole. Now, such a rock may be either a ' granitoid 



first, in 1863, to oppose the notion of a Glacial epoch in New Zealand as quite irrecon- 

 cilable with observed facts ; and he showed that the former extension of the glaciers 

 is sufficiently accounted for by the gradual reduction of the surface-area exposed 

 above the perpetual snow-line ; firstly by its erosion into valleys, ridges, and peaks ; 

 and secondly by its gradual subsidence. [See his paper Journ. Eoy. Geograph. Soc. 

 1864, p. 103; and Geol. Mag. 1870, Vol. VII. p. 95.]— Edit. Geol. Mag. 

 1 Ann. Nat. Hist. 3rd series, xx. p. 194. 



