26 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA 



the Landenian overlies the Montian, and that it contains in its lower part a benthonic 

 foraminiferal fauna comparable to that of the Thanetian of England, but with no 

 pelagic forms. He did not state to which part of the Paleocene the Thanetian 

 belongs if the " Calcaire de Mons " is considered to be of Upper Paleocene age as he 

 suggests. 



Thus, in a single paper, Hofker considered the Montian to be equivalent to the 

 upper part of the Lower Paleocene, to be Middle Paleocene in age and (as the " Cal- 

 caire de Mons ") to be of Upper Paleocene age. However, the existence of G. 

 daubjergensis Bronnimann in the " Tuffeau de Ciply ", discovered by Loeblich & 

 Tappan (1957ft), confirmed by the present author, by Gartner & Hay (1962) and by 

 Berggren (1963), throws doubt on the validity of Hofker's record, especially of G. 

 pseadomenardii and G. pusilla pusilla. In the Esna-Idfu region and in other parts 

 of the world, the last mentiond species occur at a much higher level in the Paleocene 

 succession than the uppermost limit of G. daubjergensis. Moreover, the writer has 

 examined washed residues of the " Tuffeau de Ciply" in Dr. Hofker's possession 

 and others placed by him in the collection of the Geological Museum at Haarlem 

 but could not trace these species, in spite of Hofker's statement that he had found 

 them in abundance. On the contrary, in the latter collection, forms such as G. 

 trinidadensis Bolli and G. uncinata uncinata Bolli (together with undescribed forms) 

 deny the possibility of the existence of G. pseudomenardii in the " Tuffeau de Ciply ". 

 The present author has sampled the type "Tuffeau de Ciply ", and the outcrop of 

 the " Calcaire de Mons " at the " Trenchee de Hainin " in the Mon's basin. These 

 samples together with one from the type " Calcaire de Mons " of the " Puits Goffint " 

 and several Montian samples from drilling in the Mons and the Landen Basins, 

 kindly provided by Mr. M. Gulinck and Professor R. Marliere, are still under study. 

 Until this study is completed no decision can be reached regarding the true strati- 

 graphical relationship between the Danian and the Montian. However, authors 

 have already divided into three groups ; one advocating the time-stratigraphic 

 equivalency of the type Danian and the type Montian ; another claiming a much 

 younger age for the Montian and placing it higher in the Paleocene; and a third 

 who clearly realizes the close similarity between the Danian and Montian faunas, 

 but who still advocates placing the Montian on top of the Danian. 



In support of the latter proposition, Voigt (i960) stated that " Researches now in 

 progress of the bryozoa of the Montian in Belgium and Holland show very close 

 relationship to the bryozoan fauna of the Danian, however ; a considerable part of 

 foreign, in part new, species still leaves a possibility for the lower Montian, the 

 " Tuffeau de Ciply ", to be younger than upper Danian." 



In agreement with Voigt (i960) Moskvin & Naidin (i960) recorded the occurrence, 

 in southwestern Russia (Crimea, Caucasus and Transcaspian Oblast), of a limestone 

 horizon with a molluscan fauna similar to that described from the type Montian, 

 directly overlying bryozoan and crinoidal limestone with typical Danian fauna. 

 Thus these authors concluded that the time-stratigraphic equivalency of the type 

 Danian and the type Montian as suggested by Loeblich & Tappan (1957a, b) is 



