480 Proceedings. 



moUusca, of Oamaruian and probably Awamoan age, including a form 

 resembling Strut hiolaria tuherculata, but distinguished by an enormously 

 swollen inner lip. Mudstones considerably higher up in the succession con- 

 tain a Waitotaran fauna, with such species as Verconella orhita (Hutt.), 

 Cominella ptirchasi Suter, and Pecten delicatidus Hutt. The succeeding 

 sandy and gravelly beds at the mouth of the Ruamahunga River yield 

 mostly Recent species, including Pecten delicatulus. 



The nature of the beds and the succession of the fossil faunas in the 

 Palliser Bay district show a close parallelism with those of the Awatere 

 series in Marlborough, and evidently belong to the same diastrophic sub- 

 district, characterized by a marine transgression commencing near the close 

 of the Oamaruian and extending throughout the Waitotaran, and afiecting 

 areas of pre-Notocene rocks not submerged during the lower Notocene 

 transgressions. 



Specimens of Pecten delicatulus showing clearly the ornament of both 

 valves were obtained both from Palliser Bay and from mudstones inter- 

 calated in the Wairarapa limestone at Twaite's cutting, near Martinborough. 

 These show that the assumption of Hutton, which was accepted by Suter, 

 that Pecten difluxus is a synonym of Pecten delicatulus cannot be upheld, 

 and the former must therefore be regarded a valid species. There is a Recent 

 specimen in the Dominion Museum, labelled "New Zealand," which appears 

 to be Pecten delicatulus. 



Thursday, 6th February, 1919. 



Present : Mr. P. G. Morgan, President, in the chair, and twelve others. 



Votes of thanks were passed to Mr. Speight for arranging and conducting 

 the excursion to Quail Island, Lyttelton, and to Dr. C. Coleridge Farr for 

 assistance with the lantern. 



Papers. — " The Significant Features of Reef -bordered Coasts," by 

 Professor W. M. Davis ; comnmnicated by Dr. Benson. (Printed in the 

 Transactions, pp. 6-30.) 



" Rough Ridge, Otago, and its Splintered Fault-scarp," by Dr. C. A. 

 Cotton. (Printed in the Transactions, pp. 282-85.) 



" Geography : Some Educational Aspects of the Subject," by Mr. E. K. 

 Lomas. (Printed in the N.Z. Journal of Science and Technology, vol. 2, 

 pp. 282-85, 1919.) 



'■ Report of a Committee on the Natural Features of the Arthur's 

 Pass Tunnel." by Dr. F. W. Hilgendorf. (Printed in the Transactions, 

 pp. 422-26.) 



" Range of Tertiary MoUusca in the Oamaruian of North Otago and 

 South Canterbury," by Dr. J. A. Thomson. 



ABSTRACT. 



The Oamaruian is divided into five stages, four of which are marine at 

 Oamaru and contain fossil molluscs. A very large number of fossils have 

 been collected fron^ the Oamaru, Waitaki, Waihao, Pareora, and Kakahu 

 districts by officers of the Geological Survey and others, and have been 

 determined by the late Mr. H. Suter. The plotted lists exhibited show the 

 range of each species for each of these several localities. The majority of 

 species found in the lowest, or Waiarekan, stage are also present in the 

 highest, or Awamoan, stage, but there is a small proportion confined to 

 single stages. This is particularly so in the case of the Awamoan stage, but 



