1887.] NATURAL SCIENCES OF PHILADELPHIA. 317 



sufficiently abundant as a distinguishing element in the fauna of la- 

 ter date ; and finally, the elimination of certain faunal features of 

 the period preceding, which can be passed over without further notice. 

 As far as the occurrence of the giant Edentata and of certain other 

 associated animal forms Toxodon, Macrauclienia is concerned, it 

 may be remarked that by many geologists and paleontologists the beds 

 containing their remains are referred to the Pliocene, and not to the 

 Post-Pliocene, period ; and we have now the unmistakable evidence 

 of somewhat similar, or at least related, forms being found in the 

 Miocene and Pliocene deposits of the Western United States. Nor, 

 even if we admit that these remarkable forms are exclusively Post- 

 Pliocene, can it be assumed that they are in themselves sufficient to 

 distinguish a fauna, the less so as their remains have only been 

 found in a corajiaratively limited portion of the earth's surface, and 

 have yielded no substitutes elsewhere. 



The case of man's appearance is equally inadmissible as a factor 

 in the question, since, in the first place, it is now practically certain, 

 even if positive proof in this direction is still wanting, that he al- 

 ready existed during the close of the Tertiary period, and not 

 improbably even at a much earlier date. Furthermore, his ad- 

 vent, looked at purely from the zoological stand-point, could be 

 no more a distinguishing feature in a fauna than would be the 

 advent of Dryopithecus or Hipjjopotamus. Nothing can be more 

 illogical than the assumption that because man is of all importance 

 in the faunal element of to-day, judged from the stand-point of our 

 own ca]3ricious opinions, he is of equal importance when measured 

 by the purely zoological standard. E(|ually illogical is the assump- 

 tion of a Psychozoic age as distinguished from any of the ages pre- 

 ceding. 



Having, as I believe, satisfactorily shown that the Post-Pliocene 

 series of deposits, which include the "Pleistocene," "Glacial" and 

 "Recent" of most geologists, cannot be separated as a distinct system 

 from the Tertiary, it becomes necessary to find a common name un- 

 der which all these series of deposits can be included. The term 

 Kainozoic (Cenozoic) or Tertiary, corresponding to Mesozoic or 

 Secondary, and Palaeozoic or Primary, might be conveniently retained, 

 and its application so enlarged as to embrace both the Tertiary and 

 Quaternary in use at present Quaternary, of necessity, completely 

 dropping away. 



It now remains to determine of what relative values are the major 



