388 Transactions. 



Wanganuian of Castle Point. Of the Ototara series, Ostrea nelsoniana ranges 

 from Waiarekan to Waitotaran, and Lima laevigata from Waiarekan to 

 Hutchinsonian. Of tlie Wliarekuri series, Exilia dalli has one record from 

 the Waiarekan and three from the Awamoan, while PoUnices huttoni has 

 three from the Waiarekan and seven from the Awamoan. The above ranges 

 are from my analysis of the Oamaruian fauna of Oamaru and South Canter- 

 bury described below. 



In reply to the charge of neglecting the large amoimt of palaeontological 

 knowledge we already have, I can but point to the above statements, which 

 show that it is very dangerous to generalize on our existing knowledge, and 

 which justify my caution. It seems to me that two lines of advance are 

 open. One is the more detailed study of the species on evolutionary lines 

 (such as I have been attempting in the brachiopods and limpets) with a 

 view to defining valid species of limited range, and to arrangmg the species 

 in an evolutionary order. Cossman's and Murdoch's criticisms of Suter's 

 identifications illustrate the possibilities, but the best results can be expected 

 only from an evolutionary study. The othei: is a careful, and detailed 

 analysis of the available lists with a view to discovering the range of the 

 species as at present defined. 



The procedure which promises the best results depends on the delimita- 

 tion in New Zealand of stratigraphical or diastrophic provinces within 

 the bounds of each of which the various rocks of given age are strati- 

 graphically similar and can be correlated without further demur. One such 

 district, in which none but Oamaruian marine rocks are develop«l, ranges from 

 Oamaru to Mount Somers. The sequence is everywhere — coal-beds, sands, 

 greensands, limestones, mudstones, and sands — except for some differences 

 at Oamaru and Mount Somers due to the development of volcanic rocks. 



Marshall has stated that endless confusion would be caused by attempts 

 to place the various beds near Oamaru in the stages as defined by me. If 

 this is the case in a district so simple as Oamaru, a district " midisturbed 

 by any minor stratigraphic movements," and one on which Marshall is 

 prepared to base the whole classification of the Notocene, then we may as 

 well give up all detailed stratigraphy in New Zealand. Neither Park nor 

 Uttley has encountered this endless confusion, but both have greatly 

 increased our knowledge of the district by attempts to place the beds in 

 the various stages. While it is not denied that there are difficulties, these 

 are difficulties that exist in the nature of things, and not because of the 

 adoption of certain stages, although the use of the latter has called attention 

 to them, and will probably hasten their solution. 



Taking the limestones as Ototaran [pace Park), we have the under- 

 lying rocks Waiarekan* and the overlying rocks Awamoan, the Hutchin- 

 sonian being mostly difficult of recognition, and perhaps included in the 

 upper of the two limestones that are usually to be distinguished outside 

 Oamaru. Within this province there are. numerous localities from which 

 lists of fossils have been published, and in addition Mr. Suter determined 

 all the old Geological Survey collections and also further collections made by 

 me. These lists are as yet unpublished, but the Director of the Geological 

 Survey has kindly given me access to them. I have divided the province 

 into the geographical districts of Oamaru, Waitaki Valley, Waihao, Pareora, 

 and Kakahu, and have plotted each occurrence in such a way that for each 

 stage I have retained a record of how many districts and how many localities 



* I have not taken into account Park's Bortonian, because in the type locahty 

 for this stage the fossils are practically all casts. 



o 



