icith their Characteristic Genera of Mammalia. 61 



wbich I have given expression to views not in accordance with 

 those generally accepted. 



In assigning the deposits of Pikermi, Mont Leberon, Samos, 

 Maragha, etc., to the LTpper Miocene rather than to the Lower 

 Pliocene, as advocated by the majority of palasontologists, I am not 

 aware that the considerations which formerly led me to hold this 

 view have since been invalidated. At the locality Raphina, near 

 the sea-shore, about four miles from Pikermi, Th. Fuchs came upon 

 layers intercalated with the deepest strata of the Pikermi formation 

 and containing the following shells : Ostrcea edulis, Spondylus 

 gfBcleropus, Ceritliium, Balanus, all of which still live in the 

 adjoining sea, and present a very recent aspect (" das aussere 

 Ansehen dieser Fossilien ist ausserst jugendlich, wie quaternar "). 

 Fuchs considers them to be contemporaneous with the Pikermi 

 formation ;■ as it was impossible, however, to collocate the latter with 

 the Pleistocene, he resorted to a sort of compromise by assigning 

 both to a very recent Pliocene. None of the palaeontologists who 

 have studied the fauna of Pikermi, Maragha, Mont Leberon, Samos, 

 etc., could arrive at a similar conclusion ; but in order to reconcile 

 tlie two seemingly conflicting occuri'ences, a further compromise 

 was resorted to, and Pikermi, etc., became 'Lower Pliocene.' 

 The shells being, however, undoubtedly Pleistocene, the only 

 possible explanation is the one given by De Stefani, viz., that 

 their intercalation with the Pikermi formation is the result of 

 a secondary remaniement of this latter by the sea. I think that 

 better arguments than those deduced from the presence of the 

 Eaphina shells ought to be brought forward, if the Pikermi and 

 allied formations are to be maintained in the Lower Pliocene. 



With regard to the classification of the Jurassic Mammalia as 

 ' ? Monotremata,' I have to offer the following explanation : — Part 

 of them, the Multituberculata (Allotheria), are considered by some 

 authors to have affinities with the Monotremata, and are consequently 

 placed, in the same subclass, ' Prototheria,' with the latter, whilst 

 other's prefer to assign them to a distinct suborder, collocated, 

 between the Monotremata and Marsupialia. The majority of 

 Mesozoic remains, those provided witb numerous teeth, are by 

 almost common consent united with the Polyprotodont Marsupialia. 

 With regard to the latter point, it has been observed by Winge that 

 the simple forms of the teeth and their large number in Myrmecohius, 

 several Edentates and Cetacea, are not a primitive character, but the 

 consequences of a sort of degeneration ; and further, that the shape 

 of the posterior part of the mandible in the Triconodontidge is quite 

 different from that in Marsupialia. Besides, there is some ground 

 for the assumption that the Marsupialia are merely an outcome of the 

 Placentalia. 



Therefore, with regard to the Jurassic 'Mammals' generally, since 

 their mammalian nature has not yet been raised beyond every doubt, 

 it seemed more prudent to include them all under the head of the 

 subclass or order which presents more affinities with the Eeptilia 

 than do the Marsupialia or Placentalia. 



