HuTTOX.— 0/i tlie Ages of the N.Z. Coalfields. 381 



ngarei, Pahi, &c. ; and in this way it is sought to show that 

 the two faunas are of the same age. But what is the evidence 

 for this correlation ? Mr. McKay says, "The Aniuri (iiydrauhc) 

 limestone as seen at Limestone Island, Whangarei, is, to say 

 the least of it, remarkably like the Amuri limestone at Amuri 

 Bluff, and the few fossils that have been found in that rock at 

 Whangarei, so far as they go, prove the identity of the two." 

 So that the correlation rests upon the lithological resemblance 

 of two argillaceous limestones more than three hundred miles 

 apart, and on a few fossils of which Mr. McKay gives no 

 list. Many of the fossils reported years ago as coming from 

 the Amuri limestone — including the sharks' teeth collected by 

 Mr. H. Ingles and reported by myself — probably come from a 

 higher level. At any rate, they are all found at higher levels, 

 and the only fossils I know myself from the limestone are some 

 undescribed Foraminlfcra and Ostrea snhdcniata. Mr. McKay 

 has also added Pcctcn williamsoni und BJnjiicJionella squamosa, 

 both of which also belong to the Oamaru fauna (" Eep. GeoL 

 Exp.," 1886-87, p. 90). But, supposing all the identifications 

 to be correct, and the horizon indisputable, still the evidence 

 is not important, and by no means proves the identity of the 

 two limestones. 0. snhdciitata is the only characteristic 

 species, and Mr. McKay does not say that he obtained this at 

 Whangarei ; and, if not, there is nothing to prevent the 

 hydraulic liniestone from belonging to the upper part of the 

 Oamaru series. Mr. McKay does not say that the fossils from 

 the Aniuri and hydraulic limestones are not found at other 

 horizons; but, if they arc so found, then they are not exclu- 

 sively characteristic of tlie Amuri limestone, and cannot be 

 used for identifying it. 



To make my meaning clearer, suppose the following dis- 

 tribution of fossils : — 



The Oamaru series contains species A, B. C. 

 The x\nmri limestone contains species C, D, E. 

 The ^Yaipara series contains species E, F, G. 



To prove an equivalent for the Anuiri limestone we can 

 only use D. A bed in another locality containing E might 

 belong either to the Waipara series or to the Amuri limestone, 

 a bed with C to the Oamaru series or the x\niuri limestone. 

 The last is the case with the hydraulic limestone, and, as it 

 overlies beds containing A and B, it is with the Oamaru series 

 and not with the Anuni limestone that we must correlate it. 

 In fact, if all the fossils said to come from the Amuri lime- 

 stone really do so they would only show that the Amuri lime- 

 stone forms the base of the Oamaru series in the Waipara 

 district, and would not prove it to be the equivalent of the 

 hvdraulic limestone. The pala>ontological evidence is there- 



