108 Transactions. 



age of the beds containing them, the Arapahoe and Denver beds are 

 Cretaceous, but every other consideration seems to point rather to their 

 inchision to the early Tertiary. . . . The invertebrate fauna of the 

 Denver beds is little known, and the identified species are common to 

 both the Cretaceous and Eocene."'* On page 216, in connection with the 

 relation between these formation-: in Europe, the authors say, " The break 

 between the Cretaceous and the Eocene was long regarded as one of the 

 great breaks in the geological record, but the hiatus is partially and im- 

 perfectly bridged by the estuarine, lacustrine, and other deposits of the 

 early Eocene. It is not to be lost sight of that the one period merged 

 insensibly into the next, even though the strata which recorded the 

 transition are not to be found in every region. In southern Europe the 

 separation of Cretaceous from Eocene is much less sharp, showing that the 

 notable geographic changes of the western region did not affect the southern 

 and south-eastern parts of the continent, or, at least, not to the same 

 extent." 



(a.) Western and Southern Europe. 



The most detailed treatise that is available in regard to the stratigraphy 

 of the geological formations of Europe is the " Traite de Geologic " by 

 de Lapparent. In discussing the Danian, on page 1469 of vol. iii (5th ed.), 

 he says, " Divers auteurs, notamment M. de Groussou,vre, se sont fondes sur 

 I'extinctions des ammonites pour faire du danien le premier terme du groupe 

 tertiaire. Ce qui nous determine a le laisser dans la serie neocretacee, c'est 

 le phenomene de regression qui a marque la periode danienne, et qui semble 

 mieux convenir a la fin d'une epoque qu'a I'inauguration d'une ere nouvelle." 

 Here at least it is clear that the demands of stratigraphy are given a place 

 of prior importance to the requirements of palaeontology. Later, where 

 the same author speaks of the Montian formation, he says, " Plusieurs 

 auteurs font du calcaire du Mons le terme inferieur du terrain tertiaire. 

 Pour le maintenir dans la serie neocretacee, nous nous fondons, non seulement 

 sur I'affinite paleontologique de cette assise avec le calcaire pisolithique 

 de Paris, mais aussi sur ce fait que son depot correspond a un maximum 

 de regression, precedant la grande invasion marine du debut des temps 

 tertiaires " (pp. 1470-71). Here again great importance is attached to 

 the stratigraphical aspect of the question as a criterion for deciding upon 

 the dividing plane between the Cretaceous and the Eocene. On the fol- 

 lowing pages further statements are made showing that the passage from 

 the Cretaceous to the Tertiary is to be found in a continuous series of 

 conformable sediments in Istria, in the Peloponnesus, in the Deccan of India, 

 and in Tunisia. 



(&.) Pacific Region. 



It is, however, with the Pacific region that we are mostly concerned, 

 and here it will be found that in many localities there is the greatest difficulty 

 in deciding where the Cretaceous ends and where the Tertiary begins. There 

 are at least five regions where marine fossiliferous beds show in the same 

 series both Cretaceous and Tertiary strata. These regions are California, 

 Chile, Patagonia, Seymour Island, and New Zealand. Since the descriptive 

 and critical literature in regard to the geological features of these districts 

 is scattered and not readily obtainable in this country, it is advisable to 

 summarize the main points, as they have a great importance in connection 

 with the geology of New Zealand. 



* T. C. Chamberlin and R. D. Salisbury, "Geology," vol iii, 1906, p. 158. 



