Hutton. — On Sections in Weka Pass. 263 



31. Venus meridionalis, Sowerby. 



32. Venus stictchburyi, Gray. 



33. Cytherea multistriata, Sowerby. 



34. Dosineagrayi, Zittel. 



35. Dosinea limbata, Gould. 



36. Cardita australis, Lamarck. 



37. Cucullaa alta, Sowerby (?) 



38. Pectunculus laticostatus, Quoy and Gairnard. 



39. Pectunculus c/lobosus, Hutton. 



40. Pectunculus cordatus, Hutton. 



41. Pecten diffluxus, Hutton. 



42. Pecten neozelanicus, Gray. 



43. Anomia alectus, Gray. 



44. Placunanomia neozelanica, Gray. 



45. Ostrea edulis, Linne. 



46. Waldheimia lenticularis, Deshayes. 



These beds seem to be the equivalents of the Motanau beds, 

 which have about 55 per cent, recent species, and to be younger 

 than those at the lower gorge of the Waipara, which contain 

 only 43 per cent, recent species. 



Judged by the percentage test alone, the Greta beds would 

 have to be called Pliocene, but the occurrence of Carcharodon 

 megalodon — a wide-ranging oceanic shark, highly characteristic 

 of the Miocene in Europe and North America — necessitates a 

 greater age. The high percentage of recent species may be due, 

 in part, to the liberal amount of variation that I allow to each 

 species ; but I do not think that this will account for all. It is, 

 I think, evident that the dying out of old species and the intro- 

 duction of new ones has gone on slower in New Zealand than 

 in Europe ; and it is to be expected that such has been the case, 

 for the seas of New Zealand have not been subjected to the 

 great changes in temperature which were caused in the Northern 

 Hemisphere by the glacial epoch ; nor are the facilities for im- 

 migration so great in NeAv Zealand as they are in continental 

 countries, or in Australia. 



5. Of the silt and gravel beds that succeed the Greta beds, 

 and to which, as I have already said, they appear to be uncon- 

 formable, I will merely remark that they resemble the beds 

 forming the low hills that lie between Amberly and the mouth 

 of the Waipara ; those forming the Moeraki Downs, south of 

 the Ashley ; as well as those of Eacecourse Hill, Little Eace- 

 course Hill, and Woolshed Hill near the Malvern Hills. Of 

 these, Little Eacecourse Hill is of later date than the time of 

 the greatest extension of the glaciers, for it contains large 

 angular blocks mixed up with the shingle. I suspect, therefore, 

 that these silt and gravel beds in the Weka Pass are of post* 

 glacier, but, at the same time, of Pliocene age. 



